Tetrazoyl derivatives of naturally occurring prostaglandins

ABSTRACT

The 2-descarboxy-2-(tetrazol-5-yl)- 1/8 -pentanorprostaglandins and various intermediates employed in their preparation. The novel prostaglandins of this invention have been found to have activity profiles comparable to the parent prostaglandins, but exhibit a longer duration of action than the parent prostaglandins.

United States Patent Hess et al.

[4 1 May 13, 1975 TETRAZOYL DERIVATIVES OF NATURALLY OCCURRING PROSTAGLANDINS [75] Inventors: Hans-Jiirgen E. Hess, Old Lyme;

Leonard J. Czuba, New London; Thomas K. Schaaf, Old Lyme, all of Conn.

[73] Assignee: Pfizer Inc., New York. NY.

[22] Filed: Feb. 26, 1973 21 App]. No.: 335,586

Related US. Application Data [63] Continuation-impart of Ser. No. l77 l02, Sept. l

197 I. abandoned.

[52} US. Cl t. 260/240 R; 424/269; 260/308 D; 260/345.l; 260/3478; 260/465.l; 260/468; 260/514 D [5|] Int. Cl C07d 55/00 [58] Field of Search 260/308 D, 240 R [56] References Cited FOREIGN PATENTS OR APPLICATIONS 72! L860 3/l973 Netherlands 260/240 R Primary Examiner-John D. Randolph Alrorney, Agenl, 0r FirmConnolly and Hutz [57] ABSTRACT 29 Claims, No Drawings 1 TETRAZOYL DERIVATIVES OF NATURALLY OCCURRING PROSTAGLANDINS CROSS-REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of our copending application, Ser. No. l77,l02. filed Sept. l, 1971 and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to certain novel analogs of the naturally occurring prostaglandins. In particular, it relates to novel 2-descarboxy-2-[tetrazol-5-yl1-wpentanorprostaglandins and various novel intermediates useful in their preparation.

The prostaglandins are 020 unsaturated fatty acids which exhibit diverse physiological effects. For instance, the prostaglandins of the E and A series are potent vasodilators (Bergstrom, et al., Acta Physiol. Scand. 64:332-339, 1965 and Bergstrom, et al., Life Sci. 6:449-455, l967). This relaxant effect on small blood vessels probably accounts for the fall in systemic arterial blood pressure (vasodepression) observed on intravenous injection of PGE, and PGA, (Weeks and King, Federation Proc. 231327, l964; Bergstrom, et al., 1965, op. cit.; Carlson, et al., Acta Med. Scand. l83:423-430, 1968; and Carlson et al., Acta Physiol. Scand. 75:161-169, 1969). Another well known physiological action for PGE and PGE is as a bronchodilator (Cuthbert, Brit. Med. J. 4:723-726, 1969).

Another important physiological role for the natural prostaglandins is in connection with the reproductive cycle. PGE is known to possess the ability to induce labor (Karim, et al., J. Obstet Gynaec, Brit. Cwlth. 77:200-210, 1970) and also to induce therapeutic abortion (Bygdemon, et al., Contraception, 4, 293 (197] and to be useful for control of fertility (karim, Contraception, 3, 1973 (1971). Patents have been obtained for several prostaglandins of the E and F series as inducers of labor in mammals (Belgian Pat. No. 754,158 and West German Pat. 2,034,641), and on PGF F and F for control of the reproductive cycle (South African patent 69/6089).

Still other known physiological activities for PGE, are in the inhibition of gastric acid secretion (Shaw and Ramwell, In: Worcester Symp. on Prostaglandins, New York, Wiley, l968, p. 55-64) and also of platelet aggregation (Emmons, et al., Brit. Med. J. 2:468-472, [967).

It is now known that such physiological effects will be produced in vivo for only a short period, following the administration ofa prostaglandin. A substantial body of evidence indicates that the reason for this rapid cessation of activity is that the natural prostaglandins are quickly and efficiently metabolically deactivated by -oxidation of the carboxylic acid side-chain and by oxidation of the lSa-hydroxyl group (Anggard, et al., Acta. Physiol. Scand., 81, 396 (l97l) and references cited therein).

It was, of course, considered desirable to create analogs of the prostaglandins which would have physiological activities equivalent to the natural compounds, but in which the selectivity of action and the duration of the activity would be increased.

SUMMARY OF THE INVENTION The novel compounds of this invention, the 2- descarboxy-Z- tetrazol-S-yl -w-pentanorprostaglandins, in which the carboxylic acid moiety is replaced with the tetrazol ring, and in which the lSB-hydrogen may be replaced by a lSB-lower alkyl group if desired, uniquely satisfy the above mentioned requirements. That is, they possess activity profiles comparable to the parent prostaglandins and they exhibit a longer duration of action than the parent prostaglandins, and are more selective.

Novel compounds of this invention are Z-descarboxy- 2-[tetrazol5-yl]-m-pentanorprostaglandins, and their C epimers, and the corresponding 1- and 3-lower alkyltetrazolyl pentanorprostaglandins, and their C epimers, having at the l5-position oen hydrogen or alkyl substituent having from l to 3 carbon atoms and one alkyl substituent having from 5 to l 1 carbon atoms, and the C C and C esters thereof wherein said esterifying group is formyl, alkanoyl having from 2 to 5 carbon atoms, or benzoyl.

Preferred compounds of this invention are 2- descarboxy-2-[tetrazol-S-yl]-w-pentanorprostaglandins of the A, E, or F series, and their C epimers, and the corresponding 1- and 3-lower alkyltetrazolyl pentanorprostaglandins and their C epimers, having at its l5- position one hydrogen or alkyl substituent having from 1 to 3 carbon atoms and one alkyl substituent having from 5 to l l carbon atoms, and the C,,, C and C esters thereof wherein said esterifying group is formyl, alkanoyl having from 2 to 5 carbon atoms, or benzoyl.

Such preferred compounds are represented by the formula:

wherein R is hydrogen or alkyl having I to 3 carbon atoms;

R, is alkyl having from 5 to ll carbon atoms;

W and L are each a single bond or cis double bond;

Z is single bond or trans double bond;

M is keto,

N is hydrogen or a-hydroxyl; wherein L, M and N are so selected as to complete the structure ofa prostaglandin of the A, E or F series; and the C C and C esters thereof wherein said esterifying group is formyl, alkanoyl, having from 2 to 5 carbon atoms, or benzoyl. An especially preferred series of novel compounds are represented by the formula:

wherein R is hydrogen or alkyl having l to 3 carbon atoms;

R is alkyl having from to l 1 carbon atoms;

W is a single bond or cis double bond and Z is a single bond or trans double bond;

and the C C and C esters thereof wherein said esterifying group is formyl, alkanoyl, having from 2 to 5 carbon atoms, or benzoyl.

Another especially preferred series of novel compounds is represented by the formula:

/ ll rg-v H wherein R is hydrogen or alkyl having l to 3 carbon atoms;

R is alkyl having from 5 to l 1 carbon atoms;

W is a single bond or cis double bond and Z is a single bond or trans double bond;

and the C C and C esters thereof wherein said esterifying group is formyl, alkanoy], having from 2 to 5 carbon atoms. or benzoyl.

Still other especially preferred novel compounds are represented by the formula:

wherein R is hydrogen or alkyl having 1 to 3 carbon atoms; R is alkyl having from 5 to 1 1 carbon atoms; W is a single bond or cis double bond; and Z is a single bond or trans double bond; and the C and C esters thereof wherein said esterifying group is formyl, alkanoyl, having from 2 to 5 carbon atoms, or benzoyl.

Other especially preferred novel compounds are represented by the formula:

wherein R is hydrogen or alkyl having 1 to 3 carbon atoms; R is alkyl having 5 to l 2 carbon atoms; W is a single bond or cis double bond; Z is a single bond or trans double bond; and the C esters thereof wherein said esterifying group is formyl, alkanoyl, having from 2 to 5 carbon atoms, or benzoy].

The above formulas include many preferred novel prostaglandins. Among the most important of these preferred compounds are: 2-descarboxy-2-[tetrazol-S- 4 yl PGE,; 2-descarboxy-2-[tetrazol-S-yl]PGE 2- descarboxy-2-[tetrazol-S-yl] 13,14-dihydro PGE; 2-

descarboxy-2-[tetrazol-S-yl]13,14-dihydro PGE,; 2- descarboxy-2-[tetrazol-S-yl]PGF ;2-descarboxy-2- [tetrazol-5-yl1PGl-" 2-descarboxy-2-[tetrazol-S- yl]PGF 2-descarboxy-2-[tetrazol-S-yl]PGF,p 2- descarboxy-2-[tetrazol-5-yl]PGA,; 2-descarboxy-2- [tetrazol-5-yl]PGA lS-methyl-Z-descarboxy-Z- [tetrazol-S-yllPGEg. 15-methyl-2-descarboxy-2- [tetrazol-5 yl]PGE l5-methyl-2-descarboxy-2- [tetrazol-S-yl] l 3 4-dihydro PG E l5-methyl-2- descarboxy-2-ltetrazol-S-yl]13,14-dihydro PGE,; l5- methyl-2-descarboxy-2-[tetrazol-S-yl]PGF 15 -methyl-2-descarboxy-2-[tetrazol-S-yl]PGF, a l 6, l 6 dirnethyl-2-descarboxy-2-[tetrazol-S-yl 1P0 E 16,16- dimethyl-2-descarboxy-2-[tetrazol-5-yl]PGE,; 16,16-

dimethyl-Z-descarboxy-Z-[tetrazol-S-yl] 13 4-dihydro PGE 16,l6-dimethyl-2-descarboxy2-[tetrazol-S- yl] 1 3,14-dihydro PGE,; 16, l 6-dimethyl-2-descarboxy- Z-[tetrazol-S-yHPGF and l6,l6-dimethyl-2- descarboxy-2-[tetrazol-S-ylNFC Novel reagents useful for producing the novel prostaglandins of this invention are represented by the formulae:

a (CH)PCHCH ca cn H an browherein R is hydrogen or alkyl having 1 to 3 carbon atoms; R is alkyl having from 5 to ll carbon atoms; R is Z-tetrahydropyranyl; W is a single bond or cis double bond; Z is a single bond or trans double bond.

Another series of these novel intermediates is represented by the formula:

wherein R is hydrogen or alkyl having I to 3 carbon atoms; R, is alkyl having from 5 to l l carbon atoms; Z is a single bond or a trans double bond, provided that when R is hydrogen, Z is a single bond; R is hydrogen or Z-tetrahydropyrany Expecially preferred are the cases where R is methyl and R, is n-amyl; R is hydrogen and R, is n-heptyl; and R is hydrogen and R, is l,l-dimethylpent-I-yl.

Another series of novel intermediates is represented by the formula:

wherein R is hydrogen or alkyl having 1 to 3 carbon atoms;

R, is alkyl having from 5 to l l carbon atoms;

R, is Z-tetrahydropyranyl; and

Z is a single bond or a trans double bond,

provided that when R is hydrogen, Z is a single bond.

Especially preferred are the cases wherein R is methyl and R, is n-amyl; R is hydrogen and R is nheptyl; and R is hydrogen and R, is 1,l-dimethylpentl-yl.

Another series of novel intermediates is represented by the formula:

wherein R is hydrohen or 2-tetrahydropyranyl;

R, is hydrogen, phenyl, aor BmaphthyI, or trichloromethyl;

and n is an integer of from I to 3.

Another series of novel intermeidates is represented by the formula:

. dihydro-PGF PGF, 3

wherein R is hydrogen or Z-tetrahydropyranyl; and R is hydrogen, alkanoyl having from I to 5 carbon atoms, benzoyl, p-phenylbenzoyl, or aor B-naphthoyl. A final series of novel intermediates is represented by the formula:

wherein R is hydrogen or alkyl having I to 3 carbon atoms; R, is alkyl having from 5 to l 1 carbon; and Z is a single bond or a trans double bond, provided that when R is hydrogen, 2 is a single bond.

DETAILED DESCRIPTION OF THE INVENTION For the first step in the preparation of the above named prostaglandin analogs, te appropriate hemiacetal precursor is caused to react with the disodium salt ofa novel reagent, 4-(tetrazol-S-yl)butyltriphenylphosphonium bromide, in a molar ratio of from about 1:2 1:5. Such precursors are as follows:

2-[5a-hydroxy-3oz-(tetrahydropyran-2-yloxy)-2B- (3a-(tetrahydropyran-Z-yloxy)-trans-l-octen-lyl)cyclopent-la-yllacetaldehyde, 7-hemiacetal for FGF PGF, PGE,, PGA,, POP PGF PGE PGA- l3,l4'dihydro-PGF,,, PGF, PGE,, and PGA,;

2-[5a-hydroxy-3rx-(tetrahydropyran-2-yloxy)-2B- (3/3-lower alkyl-3a-(tetrahydropyran-Lyloxy )-transl octen-1 y])cyclopent-la-yl]acetaldehyde, y-hemiacetal for the 15-lower alkyl derivatives of these same prostaglandins;

2-[5os-hydroxy-3oz-(tetrahydropyran-2-yloxyl-ZB- (3a-(tetrahydropyran-2-yloxy)oct-Lyllcyclopent-lay]]acetaldehyde, y-hemiacetal for l3,l4-dihydro PGF PGF PGE and PGA,;

2-[5a-hydroxy-3a-(tetrahydropyran-Z-yloxy)- 2B(3B-lower alkyl-3a-(tetrahydropyran-2-yloxy)-octl -yl]cyclopentl a-yl]acetaldehyde, 'y-hemiacetal for the l5-lower alkyl derivatives of l3,l4-dihydro PGFQ PGEg, and 2-[5oz-hydroxy-3a-(tetrahydropyran-Z-yloxy)-2B- (3B-( tetrahydropyran-2-yloxy )-transl -octenl yl)cyclopent-la-yl]acetaldehyde, 'y-hemiacetal for IS- epi-PGF ,PGR ,PGA,,PGE,, PGF ,PGF, PGEI PGA l3,l4-dihydro-PGF,,,, PGF, ,P E,, and PGA,;

2-[5a-hydroxy-3a-(tetrahydropyran-Z-yloxy)-2B- (3a lower alkyl-364tetrahydropyran-2-yloxy)-trans-loctenl -yl)cyclopentl a-yl ]acetaldehyde, y-hemiacetal for the l5-epi-l5-lower alkyl-P6P, POP, PGA,, PGE,, PGF PGF p PGE PGA l3,l4-

PGE,, and PGA,', 2-[-dihydro 5a-hydroxy-3a-(tetrahydropyran-Z- yloxy)-2B-(3,8-(tetrahydropyran-Z-yloxy)octlyl)cyclopent-la-yllacetaldehyde, y-hemiacetal for l5-epi-l3,l4dihyro PGF PGF PGE and 2-{ 5a-hydroxy-3a-( tetrahydropyran-2-yloxy-2B-( 30:- lower alkyl-3B-( tetrahydr0pyran-2-yloxy )octl yl)cycl0pent-la-yl]acetaldehyde, y-hemiacetal for l5- epi-lS-lower alkyl-l 3,14-dihydro PGF; PGF B PGE and PGA and 2-[5a-hydroxy-3a-(tetrahydropyran-Z-yloxy)- 2,8-( 3a-(tetrahydropyran-Z-yloxy)-cis-5-transl octadienl -yl )cyclopentcr-yl lacetaldehyde, 'y-hemiacetal for PGF PGE; and PGA;,.

The reaction will preferably be carried out at temperatures of about 2565C. in an inert solvent such as diand PGAQ tetrazoyl l3, lk-dihydro PGFla, PGF tetrazoyl Per E methylsulfoxide and in an inert atmosphere, for a period of up to about 4 hours or until the reaction is essentially complete.

The tetrazol-containing intermediates produced in the first step, as described above, may be converted by published procedures (Corey, el al., J. Am. Chem. Soc, 93, 1490 (1971) to the tetrazoyl analogs of any of the prostaglandins listed above These procedures are further described in detail in the appended examples and the steps entailed are summarized in the flow sheet below I*.ACTION SCHEZ'IE A Nat o 9 1 on (crr c N ll PGF PGF PGE and PGA tetrazoyl PGE 1, PGA 4 IRACTIOII SCIii-NF B VII As shown in Reaction Scheme A. Hemiacetal I is caused to react with the novel reagent II to produce III, the tetrazoyl analog of the bis-THP ether of PGF III PGF -tetrazoyl involves hydrolysis with aqueous acetic acid, concentration, and purification by 13, lh-dihyd ro PGFQ PC1 2 PGA III l 3,14-dihydro PGF requires a reduction with palladium on carbon and methanol to produce V which is then hydrolysed with aqueous acetic acid, and purified as above. To produce the other 13, l 4-dihydro derivatives one follows the procedures outlined above.

column chromatography. Referring now to Reaction Scheme B, Hemiacetal VI II] PGE tetrazoyl requires treatment with Jones is caused to react with the novel reagent II to produce reagent to form a second intermediate before the acid VII, the tetrazoyl analog of the bis-THP ether of l3,l4- treatment and purification as above. dihydro PGF- PGF -tetrazoyl is obtained by treating PGE VII 13,14-dihydro PGF -tetrazoy| involves hytetrazoyl with sodium borohydride, hydrolysis, concendrolysis with aqueous acetic acid, concentration. and tration, and purification by column chromatography. purification by column chromatography.

PGA -tetrazoyl is obtained by treating PGE VI] l3,l4-dihydro PGE -tetrazoyl requires treattetrazoyl with formic acid, concentration, and purificament with Jones reagent to form a second intermediate tion by column chromatogra hy, before acid treatment and purification as above.

III PGF -tetrazoyl requires a reduction with To Obtain l3l4-dihydro zp one follows the palladium on carbon and methanol to produce IV sequence above for 2 which may then be hydrolysed with aqueous acetic l y PGArIEiYaZOYI is Obtained y treating id, d ifi d as b l3,l4-dihydro PGE tetrazoyl with formic acid, con- III PGE -tetrazoyl PGF, -tetrazoyl follows exgt and Purifying y Column chromatographyacfl h same h d as outlined f the To produce the IS-epimeric, l5-lower alkyl deriva- PGE PGF series b tives, or IS-epimeric-l S-lower alkyl derivatives of all of III PGE tetrazoyI PGA -tetrazoyl f ll the above mentioned prostaglandin tetrazoyls, one actly the same method as tli d f r the PGE P. merely employs hemiacetal VIII XIII, and proceeds as 6A series ab ve above to produce the desired compound.

To produce PGF PGE and PGA;, tetrazoyl, hemiacetal XIV is employed as the starting material and all of the other reaction steps are identical to those given above.

XIV

Other intermediates may be employed in alternate preparations of the above named prostaglandin analogs. The PGF-tetrazoyls may be prepared directly by causing the appropriate hemiacetal precursor to react with the disodium salt of a novel reagent, 4(tetrazol-5- yl)butyltriphenylphosphonium bromide, in a molar ratio of from about 1:4 to 1:7. Such precursors are as follows:

2-[3a,5a-dihydroxy-2B-(3a-hydroxytrans-l-octenl-yl)cyclopent-la-yllacetaldehyde, y-hemiacetal for PGF ,PGF ,and 13,14-dihydro PGF 2-[ 3a,S0r-dihydroxy-2,8-(3B-hydroxy-transl -octenl-yl)cyclopent-la-yl]acetaldehyde, y-hemiacetal for OTHP XIII

2-[3a,5a-dihydroxy-2B-(3a-hydroxyoct-1-yl)cyclopent-la-yllacetaldehyde, 'y-hemiacetal for 13,14- dihydro PGF 2-[ 301,5 a-dihydroxy-2B-( 3B-hydroxyoct- 1 -yl )cyclopent-la-ylIacetaldehyde, y-hemiacetal for l5-eip- 13,14-dihydro PGF 2-[ 3a,5a-dihydroxy-2B-( 3B-lower alkyl-3ahydroxyoct-l-yl)-cyclopent-1a-y1]acetaldehyde, -y-hemiacetal for l5-lower -alkyl 13,14-dihydro PGF) 0:

2-[3a,5a-dihydroxy-2B-(3B-lower alkyl-3B- hydroxyoctl -yl l-cyclopentl a-yl]acetaldehyde, 'y-hemiacetal for l5-epi-l5-lower alkyl-l3,l4-dihydro PGF The reaction will preferably be carried out at temperatures of about 2565 in a solvent such as dimethylsulfoxide, and under an inert atmosphere, for a period of up to 4 hours until the reaction is essentially complete. Dilution with water, acidification extraction, concentration, and purification by column chromatography affords the PGF tetrazoyl analogs.

The PGF PGF, PGE and PGA tetrazoyl analogs may be prepared by the alternate synthesis summarized in flow sheet C. For the first step in the preparation of the above named prostaglandin analogs, the hemiacetal 2-[5a-hydroxy-3a-(tetrahydropyran-2- yloxy )-2B-benzyloxymethyl cyclopent- 1 ayl]acetaldehyde, y-hemiacetal is caused to react with the disodium salt of a novel reagent, 4-(tetrazol-5- yl)butyltriphenylphosphonium bromide as described above. This tetrazol-containing intermediate may be converted by published procedures (Corey, Schaaf, J. Org. Chem., 37, 292i (1972)) as described in detail in the appended examples as summarized below.

As shown in Reaction Scheme C, hemiacetal XV is caused to react with the novel reagent II to produce XVI.

XVI XVII involves treatment with acetic anhydride and pyridine to form a second intermediate, reduction with hydrogen and palladium on carbon in acetic acid:ethanol to form a third intermediate, and oxidation with Collins reagent.

REACTION SCHEME C PGE PGF PGF PGA tetrazoyl XVll IV requires treatment with the sodium salt of dimethyl 2-oxoheptylphosphonate to form a second intermediate, reduction with lithium tris-secbutylborohydride to form a third intermediate, treat- To examplify the greater tissue selectivity of the tetrazoyl derivatives, the threshold dose for spasmogenic effect on isolated smooth muscle from rabbit aorta, was found to be 250 ng/ml for PGE and 500 ng/ml for ment with dihydropyran to form a fourth intermediate, 5 P'GE -tetrazoyl. In this same test using guinea pig iland treatment with aqueous sodium hydroxide. eum, values of 20 ng/ml and 100 ng/ml were obtained IV PUB PGF PGF and PGA tetrazoyl for the same two compounds. one follows the procedure outlined above. In the test for effects on dog blood pressure, both The tetrazoyl analogs described above may be trans z and PGErteU'aZeyl were found to be p e formed into other types of derivatives. For example, and Values of fig/kg and #g/kg were Obie-med treatment of PGE- tetrazoyl with an ethereal solution on the two Compounds as the threshold dose for thls of diazomethane followed by concentration and colfectumn Chromatography provides both the PGE2 In contrast, in the test for protection by lOU #g/ml of methyhetrazoyl and the p052 3 N methyltetrazoyl the test compoundagamst histamine induced broncho- Furthermore, the 9,l l,l5-triesters of the PGF- l5 spasm m gumea plgsi Values of Pereent were tetrazoyls or the l l,l5-bis esters of the PGE-tetrazoyls Obtamed for both PGEZ and Y P may be prepared by treatment of the parent Compound PGE tetrazoyl appears to be a more tissue selective with the appropriate acid chloride or acid anhydride in bronchodllator h PGE? the preseme of a base Such as pyridine These proca 20 That the duration of the action ofthe lSB-lower alkyl dures are further described in detail in the appended telrazoyl l f' "lefeased Over that of e Parent examples. prostaglandln IS clearly illustrated by the data in Table I l below. This experiment demonstrates that a compa- Leger g lgc lg 22252851 3322?52212; rable drop in the blood pressure of anesthetized dogs mm was achieved with acomparable i.v. administered dose PGE2.letrazOyl P be prepared stamng wlth the 25 of the natural prostaglandin PGE or its tetrazoyl anaproprlately substituted hemlacetal and the several prog In the case of he |5 methyl PGEZ tetrazoyl cedures desFnbed These procedures are further analog, while the size of the dose must be increased to elaborated m m the appended examples achieve an equivalent drop in blood pressure, the As lle'awre Cited under Background of the length of time that this reduced pressure is maintained vention" establishes, the natural prostaglandins are is increased dramatically.

TABLE I Dog No. Compound Used Dose Recovery pig/kg lV Pre Post mm Hg Time Min.

l PGE, 4 138 l 10 28 25 PGE -Tetrazoyl 4 138 I ll) 28 31 l5-Methyl-PGE 50 l35 108 27 37 Tetrazoyl 2 2 2 I30 92 38 4 PGE -Tetrazoyl 2 I25 95 3O 6 IS-MethyHGE 128 93 35 26 Tetrazoyl 3 PGE 2 I I5 92 23 6 PGE, 2 l 14 24 ll) l5-Methyl-PGE 50 1 I4 90 24 I20 Tetrazoyl 4 E 2 I30 I00 30 6 lGE -Tetrazoyl 2 132 1 I0 22 6 IS-methyl-PGE 50 136 MB 33 30 Tetrazoyl 5 2 2 1 I5 82 33 S PGE Tetrazoyl 2 l H] 90 3O 8 l S-Methyl-PGE 50 l 20 92 28 4O Tetrazoyl Blood pressure before administration of drug. Blood pressure after administration of drug.

known to exhibit a spectrum of physiological activities. in numerous in vivo and in vitro tests we have demonstrated that the tetrazoyl prostaglandin analogs possess the same physiological activities as the natural prostaglandins with greater selectivity of action. These tests include, among others, a test for effect on isolated smoooth muscle from rabbit aorta and guinea pig ileum, a test for inhibition or norepinephrine induced lipolysis in isolated rat fat cells, a test for effect on histamine induced bronchospasm in guinea pig. :1 test for effects on dog blood pressure, and a test for effects on rat blood pressure.

The new compounds of this invention can be used in a variety of pharmaceutical preparations and they may be adminstered by a variety of routes, such as intravenous, oral and topical including aerosol, intravaginal, and intranasal among others. The dosage amounts and dosage routes for the new compounds of the invention generally are equivalent to those of the corresponding natural prostaglandins for the selected utility. This is verified by the following exemplary dosage forms and amounts illustrated below for specific compounds.

The natural prostaglandins of the E and P series are well known agents for the induction of abortion, and

the corresponding tetrazoyl prostaglandins share this utility. For such treatment an aqueous suspension of PGE or PGF a -tetrazoyl is appropriately administered at a level of from about 0.2-5.0 mg/dose for PGE tetrazoyl or 3.0-50 mg/dose for PGF- a tetrazoyl with from 1 to 7 oral doses per day being employed in either case.

If an intravaginal treatment for abortion induction is desired, a suitable agent is a sterile ethanolic solution of either of these two tetrazoyl prostaglandins or lactose tablets of the same two agents. In such treatments suitable doses are from 15-200 mg/dose for PGE tetrazoyl or from 35-250 mg/dose for PGF tetrazoyl with l or 2 doses being employed.

In cases where a midterm abortion is necessary, an effective agent is an ethanol-dextrose solution of PGE tetrazoyl administered as an intravenous infusion. A suitable dosage is from about 5-500 ug/min administered for a period of from l-24 hours.

If an intra-amniotic treatment for midterm abortion is necessary, an effective agent is a sterile ethanolic solution of either PGE or PGF -tetrazoy1administered directly into the amniotic sac by means of a polyethylene catheter. A suitable dose is from 0.5-5.0 mg/dose for PGE -tetrazoyl or 5-50 mg/dose for PGF -tetrazoyl with from 1 to 5 doses administered.

Another use for the tetrazoyl prostaglandins is as an inducer of labor. For this purpose an ethanol-saline solution of PGEg-t3t1'3ZOYl is employed as an intravenous infusion in the amount of from about 33-100 ug/kg/min for from 1-10 hours.

Still other applications for the E-series prostaglandintetrazoyls are to produce bronchodilation or to increase nasal patency. An appropriate dosage form for this use is an aqueous ethanolic solution of PGE or PGE, -tetraz0y1 which for bronchodilator use is employed as an aerosol using fluorinated hydrocarbons as propellant in the amount of from about 3-500 ug/dose.

A use for A- series tetrazoyl prostaglandins is as antihypertensive agents. For such a treatment an ethanol solution of PGA, or PfiA -tetrazoyl is appropriately administered as an intravenous infusion at about I-30 ug/kg/min for a total dose of from l-20 mg/kg/day.

The utility and dosage amounts of the -lower alkyl substituted tetrazoyl prostagladins generally parallels that of the IS-desalkyl derivatives.

To prepare any of the above dosage forms or any of the numerous other forms possible, various reactioninert diluents, excipients or carriers may be employed. Such substances include, for example, water, ethanol, gelatins, lactose, starches, magnesium stearate, talc, vegetable oils, benzyl alcohols, gums, polyalkylene glycols, petroleum jelly, cholesterol, and other known carriers for medicaments. If desired, these pharmaceutical compositions may contain auxiliary substances such as preserving agents, wetting agents, stabilizing agents, or other therapeutic agents such as antibiotics.

It will be seen that the formulae appearing in the foregoing depict optically active compounds. it will be clear, however, that the corresponding racemates will exhibit valuable biological activity by virtue of their content of the above-mentioned biologically active optical isomer, and it is intended that such racemates also be embraced by the foregoing formulae herein and in the appended claims. The racemic mixtures are readily prepared by the same methods employed herein to synthesize the optically active species, by mere substitution of corresponding racemic precursors in place of optically active starting materials.

The following examples are merely illustrative, and in no way limit the scope of the appended claims. All temperatures are given in degrees Centigrade and all percentages are by weight.

EXAMPLE 1 Anal. Calcd for C H BrNP:

Found:

C, 65.10; H, 5.47; N, 3.30 C, 65.01; H, 5.40; N, 3.19.

A mixture of the phosphonium salt above (10.0 g., 23.5 mmoles), ammonium chloride (1.60 g., 30.0 mmoles), lithium chloride (0.032 g., 0.76 mmole), sodium azide (1.91 g., 23.9 mmoles), and dimethylformamide (50 ml.) was heated to 127 (oil bath) under nitrogen with stirring for 18 hours. The resulting suspension was cooled and filtered. The residue was washed with dimethylformamide and the combined filtrate and washings were concentrated (aspirator pressure, ca. 45). The oily residue was crystallized from water at 0 and air dried to give a white crystalline solid (8.1 l g.), m.p. -102. The product was recrystallized from methanol-ether to give white prisms (7.18 g.), m.p. 197-206. An analytical sample was prepared by recrystallization from 2-propanol to give a white crystalline powder, m.p. 212-213, which was 4-(tetrazo1-5- yl)butyltriphenylphosphonium bromide.

Anal. Calcd for C H l-hPBr: C, 59.10; H, 5.17; N, 1 1.99:

P, 6.63; Br. 17.09.

Found: C 59.35; H, 5.28;

EXAMPLE 11 Sodium hydridemineral oil dispersion (56.6 percent, 2.12 g., 1.20 g. dry powder) was washed with three portions of pentane under dry nitrogen. The resulting gray powder was stirred with dry dimethylsulfoxide (25 ml. distilled from CaH bp ca. 60 at 6 mm) under nitrogen at 60-65 for 2 hours to give a cloudy, gray solution. The solution was cooled, and an aliquot was diluted with water and was titrated to a phenolphthalien end point with 0.100N hydrochloric acid to determine a molarity of 2.07. A portion of the standardized solution (5.36 ml., 11.1 mmoles) was added dropwise over a 15 min. period to a stirred solution of the final phosphonium salt of Example I (2.70 g., 5.78 mmoles) in dry dimethylsulfoxide (8 ml.) under nitrogen at room temperature. To the resulting red solution was added a solution of 2-[5a-hydroxy-3a-(tetrahydropyran-Z-yloxy)- 2B-( 3a-tetrahydropyran-2-yloxy)-transl -octen- 1- yl(cyclopentla-yl]acetaldehyde, y-hemiacetal[- known compound, see E. J. Corey, et a1., 1. Am. Chem. Soc., 92, 397 (1970), 1.00 g., 2.28 mmoleslin dimethylsulfoxide (6 m1.) over a 50 min. period while stirring the mixture under nitrogen at room temperature. The

mixture was stirred for an additional 2 /2 hours and then was poured into ice-water l ml.). The aqueous mixture was acidified with 1.0N hydrochloric acid (I LS ml.) and extracted with three 50-ml. portions of ethyl acetate. The extract was washed with water (20 ml. dried (MgSO and concentrated (aspirator pressure, ca. 40) to give a red oil (2.5l g.). The crude oil was chromatographed on 60-200 mesh silica gel (50 g.) using chloroform. ethyl acetate and methanol as successive eluents to separate a mixture containing mostly triphenylphosphine oxide (1.05 g). unchanged starting material (0.18 g., 18 percent recovery), the expected product, 3B-[3a(tetrahydropyran- 2yloxy) trans-l-octen-l-yl]-2a[6-(tetrazol-5-yl)-cis-2-hexen-lyl]-4a-(tetrahydropyran-2-yloxy)cyclopentan-la-ol as a thick colorless oil (0.650 g., 50.5 percent yield), and a mixture of expected product and unidentified products (0.459 g.) The fractions were identified by thin layer chromatography on neutral silica gel glass plates using ethyl acetate or chloroform-methanol (5:l) as developer and the chromatograms were visualized by heating with a vanillin-phosphoric acid reagent. The expected product exhibited R, values of 0.22 and 0.72, respectively, with these two developing systems. This compound is an important intermediate in the synthesis of tetrazoyl analogs of several prostaglandins, as is illustrated below.

EXAMPLE "I A mixture of the his THP ether of Example ll (333 mg., 0.6l4 mmoles), acetic acid (6.5 ml.) and water (3.5 ml.) was stirred under nitrogen for 4 hours at 40-45. The resulting clear solution was concentrated (aspirator pressure, ca. 40) and the residue (335 mg.) was partitioned between water (20 ml.) and ethyl acetate (20 ml. The ethyl acetate layer was separated and combined with an ethyl acetate extract (20 ml.) of the aqueous layer. The combined ethyl acetate solutions were washed with brine (20 ml.), dried (Na son and concentrated (aspirator pressure ca. 40) leaving a clear, faintly tan oil (223 mg). The oil was chromatographed on acidic silica gel g., Malinckrodt Silicar CC4, l00-200 mesh) using chloroform followed by mixtures of chloroform and methanol as eluents to separate an unidentified mixture (87 mg.) and the desired product. 3B-(3a-hydroxy-trans-locten-l-yl)2a[6- (tetrazol-5-yl)-cis- 2-hexen-l-yl]-cyclopentan-la, 4adiol, as a thick colorless oil I03 mg, yield 44 percent). Thin layer chromatograph of product on silica gel glass plates using chloroform-methanol (5:1) as the devel oper and visualizing the chromatogram by heating with vanillin-phosphoric acid reagent showed a single spot at R] 0.13. This product is 2-descarboxy 2(tetrazol- 5'yl) PGF The above product may be hydrogenated as described in Example VA to provide 3B-(3cx-hydroxyoct -lyl)-2a-[6-(tetrazol-5'yl)hexl -yl]cyclopentan la, 4a-diol EXAMPLE IA To a solution of the 4-(tetrazol-5-yl)butyltriphenylphosphonium bromide prepared in Example I (4.65 g.; 10.0 m moles) in 50 ml. ofdry tetrahydrofuran is added a solution of diazomethane in ether until the reaction solution remains yellow for 5 minutes. Concentration followed by chromatographic purification affords the desired 4-( lNmethyltetrazol-5-yl)butyl-triphenylphosphonium bromide and 4-(3-N-methyltetrazol-5- yl)butyltriphenylphosphonium bromide.

These compounds may be converted by methods both known (see: E. J. Corey, et al., J. Am. Chem. Soc., 92, 397 (1970) and described herein to the 2- descarboxy-2-( l-N-methyltetrazol-S-yl) and 2- descarboxy-2-( 3-N-methyltetrazol-5-yl )prostagladin s.

EXAMAPLE IV To a stirred solution of the bis THP ether of Example ll (400 mg, 0.731 mmoles) in acetone (12.3 ml.) at 10 was added, dropwise over a 5 minute period, 0.29 ml. of Jones reagent previously prepared from 2.67 g. chromium trioxide and 2.3 ml. concentrated sulfuric acid diluted to l0 ml. volume with water. The resulting mixture was aged for l5 minutes at l0 and then treated with isopropyl alcohol (0.46 ml.). The mixture was stirred for an additional 5 minutes at l 0' and partitioned between ethyl acetate (30 ml.) and water (30 ml.). The ethyl acetate layer was separated and combined with an ethyl acetate extract of the aqueous layer. The combined solutions were washed with three 15-ml. portions of water, dried (MgSOQ, and concentrated (aspirator pressure, ca. 4050) leaving 358 mg. of 4a-(tetrahydropyran-Z-yloxy)-3B{ 3a- (tetrahydropyran2-yloxy)-transl -octenl -yl ]-b 20:- [6-(tetrazol-5-yl)-cis2-hexenl-yl]cyclopentanone as a viscous oil.

EXAMPLE V The oil produced in Example IV was stirred with acetic acid (l0.7 ml.) and water (5.8 ml.) under nitrogen at 40-45 for 3 hours. The resulting solution was concentrated (aspirator pressure, ca. 4050) and the residue (275 mg.) was chromatographed on acidic silica gel (25 g., Malincrodt Silicar CC-4, 200 mesh) using mixtures of chloroform and methanol as the eluent to separate an unidentified mixture mg.) and the desired product, 4a-hydroxy-3B-(3a-hydroxytrans-l-octen-1-yl)-2a-[6-(tetrazol-S-yl)-cis-2-hexenl-yllcyclopentanone, as a clear, thick, colorless oil (103 mg, 37 percent). Thin layer chromatography of the product on silica gel glass plates using methylene chloridemethanol (9:1) or benzene-tetrahydrofuranformic acid (l5:5:2) as the developers and visualizing the chromatograms by heating with vanillinphosphoric acid reagent showed a single spot with R values of 0.30 and 0.25 on the two systems, respectively. The ir spectrum (CHCl of the product exhibited a strong absorption band at 1730 cm (C=O) and a moderately weak band at 36l0 cm (OH). The uv spectrum (95% EtOH) of the product showed only end absorption. This product is 2-descarboxy-2-(tetrazol-5-yl)PGE Treatment of a small sample of the product with 10 percent aqueous sodium hydroxide and ethanol for 15 minutes at room temperature gave a single product by tlc (R,0.38, silica gel, benzene-tetrahydrofuran-formic acid. 15:52). The uv spectrum (95% EtOH) of the latter product exhibited an absorption maximum at 279 mp. (19,600).

EXAMPLE VA A heterogeneous mixture of the product of Example V l47 mg; 0.390 mmole) and 45 mg. of 5 percent palladium on carbon in 20 ml. of absolute methanol was stirred under 1 atmosphere of hydrogen for 2.0 hours at room temperature. The reaction was then filtered through a pad of Celite and concentrated. Purification of the crude product by silica gel chromatography (Mallinckrodt CC-4) using mixtures of methanol in chloroform as eluents afforded the desired 4a-hydroxy- 3B-( 3ahydroxyoctl -yl )-2o:-[6-( tetrazol-S-yl)hex-l yllcyclopentanone as a colorless oil weighing 47 mg.

The mass spectrum of the product exhibited a peak at mle 362 for M-H O. The ir spectrum'of the product exhibited a strong absorption at 1740 cm for the ketone carbonyl and no absorption at 970 cm for the trans olefin.

EXAMPLE VB A heterogeneous mixture of 148 mg. (0.400 mmole) of the product of Example V and 45 mg, of 5 percent palladium on carbon in l5 ml. of absolute methanol was stirred under I atmosphere at for 2.0 hours (one equivalent of hydrogen was consumed). The reaction was then filtered through a pad of Celite and concentrated. Purification of the crude product using mixtures of methanol in ethyl acetate afforded the desired 40:- hydroxy-3,8( 3a-hydroxy-transl -octenl -yl)-2a-[ 6- (tetrazol--yl)hex-l-yll-cyclopentanone as a viscous, colorless oil weighing 22 mg.

The nmr spectrum (CD OD) of the product exhibited a multiplet at 5.72-5.5l 8 for the trans olefin, a multiplet at 4.l9-3.80 5 for the C110, a triplet at 2.93 6 (J 7 cps) for the Clj -tet, and multiplets at 2.76-0.60 8 for the remaining protons.

This prostaglandin analog may be converted by the process of Example IX to 2-descarboxy-2-(tetrazol-S- yl)PGA and by the process of Example XXIII to 2- descarboxy-2-(tetrazol-S-yDPGF,

EXAMPLE VI A mixture of the his THP ether produced in Example I] (198 mg.). a 5 percent palladium on carbon (200 mg.) and methanol (l0 ml.) was stirred under one atmosphere of hydrogen for 65 hours at room temperature. The mixture was filtered and the filtrate was concentrated (aspirator pressure, ca. 40") to give I32 mg. of a thick, colorless oil 3B-[3a-(tetrahydropyran-2- yloxy)oct-1-yl]-2a-{6-(tetrazol-5-yl)-hex-l-yl]-4oz- (tetrahydropyran-2-yloxy)cyclopentan-la-ol. The thin layer chromatogram of the product showed a single spot which was not distinguishable from that of the starting material (from Example II) as described above. The product was identified by a hydrolysis experiment in which the R; of the hydrolysed product was found to be 0.20 while the R, of the hydrolysis product of the starting material was 0.13.

EXAMPLE VII EXAMPLE VIII The product of Example VI (l3l mg.) was oxidized with Jones reagent (0.094 ml.) as described above in Example V. Isolation of the product and subsequent 2-descarboxy-2-(tetrazol-S-yl)l 3,14-

hydrolysis yielded the pure product 4a-hydroxy-3B- (3a-hydroxyoct-l-yl)-2a-[6-(tetrazol-5-yl)hexl-yllcyclopentanone as a thick, clear, colorless oil (49 mg.). Thin layer chromatography of the product on silica gel glass plates developed with methylene chloridemethanol (9:1) showed a single spot (vanillinphosphoric acid indicator) with an R, 0.3 l. The infrared spectrum (CHCl of the product showed a strong absorption band at 1730 cm (C=O) and a moderately weak band at 3610 cm (OH). This product is 2 descarboxy-2-(tetrazol-S-yl)-l3,14-dihydro PGE,. The uv spectrum percent EtOH) of the product exhibited only end absorption, and treatment of the uv spectrum sample with 40 percent potassium hydroxide did not form a product(s) with significant absorption maxima in the 220-300 my. region of the spectrum.

This prostaglandin analog may be converted by the process of Example IX to 4B(3a-hydroxyoct-l -yl)-5a- [6-(tetrazol-5-yl)hex-1-yl]cyclopent-2en-l-one, 2- descarboxy-2-(tetrazol-S-yl)-l 3, l 4-dihydro PGA and by the process of Example XXIII to 2-descarboxy-2- (tetrazol-5-yl)-13,l4-dihydro PFG EXAMPLE IX The product of Example V (45 mg.) was stirred with 97% formic acid (0.18 ml.) for 2 /2 hours. The resulting mixture was diluted with ice-water (ca. 4 ml.). The aqueous mixture was extracted with three 5-ml. portions of ethyl acetate. The extract was dried (Na SO and concentrated (aspirator pressure, ca. 40-50) to give a crude oil (39 mg.). Chromatography of the crude product on acidic silica gel (4 g., Malinckrodt CC-4, l00-200 mesh) using mixtures of chloroform and methanol as the eluent to separate the desired product 4B-( 3a-hydroxy-transl -octenl -yl)-5a-[ 6-(tetrazol-5- yl)-cis-2-hexen-l-yl]cyclopent-2en-l-one, as a thick, colorless oil (l0 mg.) and an unidentified product 17 mg.). Thin layer chromatography of the product on silica gel glass plates developed with benzene-tetrahydrofuran-formic acid (15:5:2) showed a single spot (vanillin-phosphoric acid indicator) with an R, 0.50. The infrared spectrum (CHCI of the product showed a strong absorption band at l7l0 cm (conjugated C=O in a five-membered ring) and a moderately weak band at 36l0 cm (OH). The uv spectrum (95% EtOH) of the product exhibited an absorption maximum at 222 mu. This product is 2-descarboxy-2- (tetrazol-S-yl) PGA EXAMPLE X To a solution cooled to 78 of 2.68 g. (6.00 mmoles) of 2-[3a-p-biphenyl-carboxy-Sa-hydroxy-ZB- [3-oxo-trans-1-octen-1-yl]cycIopent-loz-yl]acetic acid, 'y-lactone, a known compound (see reference for Example II), in 26 ml. of anhydrous ether (Mallinckrodt) and 20 ml. of tetrahydrofuran (distilled from lithium aluminum hydride) was added dropwise 6.5 ml. (6.00 mmoles) ofa 0.92 N solution of methyllithium in ether (Alfa). After being stirred at 78 for IS minutes the reaction was quenched by the dropwise addition of glacial acetic acid until the pH of the reaction was approximately 7. The mixture was then diluted with methylene chloride and the diluted organic solution was washed with water (IX) and with saturated brine (IX), was dried (anhydrous magnesium sulfate), and was concentrated to afford 2.7l g. of the viscous, oily epimeric alcohols (97.8 percent yield).

The crude product was purified by column chromatography on 108 g. of silica gel (Baker Analyzed Reagent 60-200 mesh) using a mixture of benzene:ethyl acetate as eluent. After elution of higher R impurities. the desired la-hydroxy-l5B-methyl epimer, 2[3oz-p biphenylcarboxy-Sa-hydroxy-ZB-l3a-hydroxy-3B- methyl-trans-l-octen-yllcyclopent -la-yl]acetic acid. y-lactone, was eluted weighing 0.853 g. (30.8 percent yield). Thin layer chromatography of the product on silica gel glass plates using a :1 mixture of ether:2- butanone as eluent showed a single spot having an R, 0.45.

The ir spectrum (CHCl of the product exhibited strong absorptions at 1710 cm for the ester carbonyl and 1770 cm for the lactone carbonyl. The nmr spectrum (CDClg) of the product showed a multiplet at 7.28-8.22 6 for the aromatic protons, a multiplet at 5.56-5.77 5 for the olefinic protons, a multiplet at 4.90-5.45 8 for the -CHOCO-, a singlet at 1.27 8 (5 and multiplets at 0.5 7-3. 10 8 for the remaining protons.

The above product may be reduced according to the procedure of Example XXXll to provide 2-[2/3-(35- methyl-SB-hydroxy-transl -octenl -yl )-3a, 5adihydroxycyclopent-la-yllacetaldehyde, 'y-hemiacetal. This compound may be converted according to the procedure of Example XXXIII to l5-methyl-2- descarboxy-2-(tetrazol-S-yl)PGF a EXAMPLE X1 A heterogeneous mixture of 1.30 g. (2.81 mmoles) of the chromatographed ester of Example X, ml. of methanol, and 0.388 g. (2.81 mmoles) finely powdered anhydrous potassium carbonate was stirred under nitrogen for 2.0 hours at room temperature then was cooled in ice. To the cooled solution was added 5.60 ml. (5.60 mmoles) of 1.0 N hydrochloric acid. The cold, acidified solution was stirred for 10 minutes then was diluted with 25 ml. of saturated brine. After filtration of the resultant solids the filtrate was extracted with ethyl acetate (3X). The combined ethyl acetate extracts were washed with water l X), were dried (anhydrous magnesium sulfate), and were concentrated to afford 0.744 g. (94.0 percent yield) of a yellow, oily diol. 2-l3a, 5a-dihydroxy-2B-(3a-hydroxy-3B-methyl trans-l-octen-1-yl)cyclopent-loz-yllacetic acid, y-lactone.

This oil was purified by column chromatography om silica gel (Baker Analyzed Reagent 60-200 mesh) using a 1 :1 mixture of methylene chloride: ethyl acetate as eluent. After elution of higher R, impurities 0.507 g. of the desired diol was collected (64.0 percent yield). Thin layer chromatography of the diol product on silica gel glass plates using a 9:1 mixture of methylene chloride: methanol as eluent showed a single spot having an R 0.65.

The ir spectrum (CHCI of the diol exhibited a strong absorption at 1770 cm for the lactone carbonyl. The nmr spectrum (CDCl of the diol product exhibited a multiplet at 5.46-5.70 5 for the olefinic protons. a multiplet at 4.75-5.14 5 for the HO-Cl -1 a multiplet at 3.75-4.21 8 for the flCOCO-, a singlet at 1.26 5 for the H multiplets at 0.68-3.1 l 5 for the remaining protons.

EXAMPLE Xll To a solution, cooled in ice, of 0.507 g. (1.80 mmole) of the Chromatographed diol of Example X1 in 5.4 ml. of methylene chloride was added 0.54 ml. of dihydropyran (distilled from lithium aluminum hydride). and 18 mg. of p-toluenesulfonic acid monohydrate. The solution was stirred in the cold for 15 minutes then was diluted with ether. The organic solution was washed with saturated sodium bicarbonate (1X). was dried (anhydrous magnesium sulfate), and was concentrated to afford 0.870 g. (107 percent yield] of the paleyellow, oily bis-THP ether 2-l5a-hydroxy3a- (tetrahydropyran-Z-yloxy)-2,B-methyl-3a- (tetrahydropyran-2-yloxy)-trans-l-octen-1- yl)cyclopent-la-yllacetic acid, y-lactone, which was used without further purification. Thin layer chromatography of the oily product on silica gel glass plates using 5 percent methanol in methylene chloride as eluent showed a single spot having an R 0.85. The structure of the product was substantiated by the virtual identity of its ir spectrum with that of the known 15- normethyl compound (see reference for Example 11).

The above product may be hydrogenated according to the procedure of Example VA to provide 2-[501- hydroxy-3 a-(tetrahydropyran-2y1oxy )-2B-( 3 B- methyl-3a-(tetrahydropyran-Z-yloxy )octl yl)cyclopent-l a-yllacetic acid, y-lactone.

This product may be reduced according to the procedure of Example Xlll to afford 2-[5a-hydroxy-3a- (tetrahydropyran-Z-yloxy )-2B-( 3B-methyl-3a- (tetrahydropyran-IZ-yloxy)oct-1-y1)cyclopent-l ayllacetaldehyde, y-hemiacetal. a compound necessary for the preparation of 15-methyl-2-descarboxy2- (tetrazol-5-yl)-13,14-dihydro PGF a PGF B PGE and PGA EXAMPLE X111 To a solution cooled to -78 of 0.810 g. (1.80 mmoles) of the crude his-THP ether lactone of Example X11 in toluene was added 2.3 ml. (1.85 mmoles) of a 0.805 M solution of diisobutylaluminum hydride in hexane (Alfa). The solution was stirred at 78 for 15 minutes then was quenched by the dropwise addition of methanol until gas evolution ceased. The quenched mixture was warmed to room temperature then was concentrated. The resultant oil was dissolved in ether and the ethereal solution was washed with a 50 percent sodium potassium tartrate solution (2X) and with saturated brine 1X), was dried (anhydrous magnesium sulfate), and was concentrated to afford 0.800 g. (98.5 percent yield) of the oily hemiacetal 2-[5ot-hydroxy- 3ot-(tetrahydropyran-2-yloxy)-2{3-(3B-methyl-3a- (tetrahydropyran-Z-yloxy)-trans-1-octen-1-yl)cyclopent-l a-yl] acetaldehyde, y-hemiacetal.

The oil was purified by column chromatography on silica gel (Baker Analyzed Reagent 60-200 mesh) using first benzene as eluent to remove high R; impurities then a 2:1 mixture of benzenecethyl acetate to elute the colorless, oily product weighing 0.601 g. (74.0 percent yield). Thin layer chromatography of the oily product on silica gel glass plates using a 4:1 mixture of benzene:ethyl acetate as eluent showed a single spot having an R 0.10. The structure was confirmed by the virtual identity of its ir spectrum with that of the known lS-normethyl compound (see reference for Example [1).

EXAMPLE XIV To a solution of 0.985 g. (2.08 mmoles) of the bromide of EXAMPLE I in 1.94 ml. of dimethyl sulfoxide was added dropwise 2.38 ml. (5.24 mmoles) ofa 2.2 M sodium methylsulfinylmethide solution. To the resultant red ylide solution was added dropwise over a 20 minute period a solution of 0.375 g. (0.83 mmole) of the chromatographed hemiacetal of Example XIII in 1.66 ml. of dimethyl sulfoxide. The solution was stirred for an additional 2.5 hours then was poured onto 50 ml. of ice water. The aqueous solution was acidified to pH 3 with percent hydrochloric acid. The aqueous layer was then extracted with ethyl acetate (5X); the combined organic extracts were dried (anhydrous magnesium sulfate) and were concentrated to afford an oil weighing 0.987 g.

This oil was purified by column chromatography on 40 g. of silica gel (Baker Analyzed Reagent 60-200 mesh) using 10 percent ethyl acetate in chloroform as eluent. After elution of higher R; impurities, 185 mg. (49.4 percent yield) of starting hemiacetal were recovered. Further elution afforded 90 mg. (26.9 percent yield based on unrecovered starting hemiacetal of the oily product la-hydroxy-4a-(tetrahydropyran-Z- yloxy )-3B-[ 3B-methyl-3a-(tetrahydropyran-2-yloxy)- transl -octenl -yl]-2oz-[ 6-(tetrazol-5-yl )-cis-2-hexenl-yllcyclopentane (herein called compound A). Thin layer chromatography of the oily product on silica gel glass plates using 10 percent methanol in methylene chloride as eluent showed a single spot having an Rf 0.40.

The structure of the product was confirmed by the virtual identity of its ir spectrum with that of the normethyl compound (see Example II).

The above compound A may be converted by the process of Example VI to la-hydroxy-3B-[3B-methyl- 30z-(tetrahydropyran-Z-yloxy)octl -yl]-2a-[6- (tetrazol-S-yl )hexl -yl ]-4oz-(tetrahydropyran-Z-yloxy cyclopentane, an intermediate which can be converted by the process of Example VII to la,4a-dihydroxy-3B- (3a-hydroxy-3B-methyloctl -yl )-2a-[ 6-(tetrazol-5- yl)hex-1-yl]cyclopentane, 2-descarboxy-2-(tetrazol-S- yl)-15-methyl-13.14-dihydro PGF, or by the process of Example XIV above to 4a-(tetrahydropyran-2- yloxy)-3B-[3B-methyl-3a-(tetrahydropyran-Z- yloxy )octl -yl]-2a-[ 6-(tetrazol-5-yl )hexl yllcyclopentanone, another important intermediate.

This last named intermediate may be converted by the process of Example XVII to 4a-hydroxy-3B-[3ahydroxy-3B-methyloct- I -yl 2a-[ 6-( tetrazol-5-yl)hexl-yllcyclopentanone, 2-descarboxy-2-(tetrazol-S-yl)- l5-methyl-l3,14-dihydro PGE The 2-descarboxy-2-(tetrazol-5-yl)- l S-methyll3,l4-dihydro-PGE may be converted by the method of Example 1X to 4B-[3a-hydroxy-3B-methyloct-lyl]- 5a-[6-(tetrazol-5-yl )hexl -yl]cyclopent-2en- 1 -one, 2- descarboxy 2-(tetrazol-S-yl)-l S-methyl- 13.14-dihydro PGA The 2-descarboxy-2(tetrazol-5-yl )-l S-methyl- 13.14-dihydro-PGE, may be converted by the method of Example XXIII to 2-descarboxy-2-(tetrazoI-S-yl)- l5-methyl-1 3,14-dihydro PGF The important intermediate compound A may also be converted by a modified process of Example VI wherein the reaction temperature is to lahydroxy-4a-(tetrahydropyran-Z-yloxy)-3B[3,B- methyl-3a(tetrahydropyran-2-yloxy)-transl -octen-1- yl]-2a-[6-(tetrazol-5-yl-hex-l-yl]cyclopentane. (herein called compound B). Compound B may be converted by the process of Example XV to la, 4adihydroxy-3/3-[3a-hydroxy3B-methyl-trans-loctenyl]-2a-[6-(tetrazol-5-yI)-hex-l-yllcyclopentane. 2-descarboxy-2-(tetrazol-S-yl)-l S-methyl PGF a Compound B above may be converted by the process of Example XIV to 4a-(tetrahydropyran-Z-yloxy)-3B- [3B-methyI-3a-(tetrahydropyrari-Z-yloxy)-trans-locten-1-yl]-2a-[6-(tetrazol-5-yI)-hex-lyl]cyclopentanone, another important intermediate, which may be further converted by the process of Example XVII to 4a-hydroxy-3B-[ 3a-hydroxy-3B-methyl trans-l-octen-l-yl]-2a-[6-(tetrazol-5-yl)-hex-lyllcyclopentanone. 2-descarboxy-2-(tetrazol-S-yl l 5- methyl PGE The tetrazoyl analog of l5-methyl PGE, may be con verted by the process of Example IX to 4B-(3ahydroxy-3B-methyl-transl -octenl -yl )5a-[ 6- (tetrazol-S-yU-hex-l-yl]cyclopent-2-ene-l-one, the 2- descarboxy-2-(tetrazol-S-yl)-l 5-methyl PGA The tetrazoyl analog of IS-methyl PGE may be converted by the process of Example XXIII to the 2- descarboxy-2-(tetrazol-S-yl)-lS'methyI PGF p EXAMPLE XV A solution of 8.0 mg. of the bis-THP ether of Example XIV in 0.40 ml. of a 65:35 mixture of acetic acid:- water was stirred at 40 for 5.0 hours then was concentrated by rotary evaporation. The crude oil was purified by column chromatography on silica gel (Mallinckrodt CC-4) using 5 percent methanol in chloroform as eluent. A 3.5 -mg. portion of the oily triol. la, 4adihydroxy-3B-[ 3a-hydroxy-3B-methyl-transl -octenl yl}-2a-[6-(tetrazol-5-yl)-cis-2-hexenlyl]cyclopentane was obtained.

The structure of the oily triol was substantiated by the virtual identity of its ir spectrum with that of the known l5 normethyl compound (see Example III). This compound is the 2-descarboxy-2-(tetrazol-S-yl)- IS-methyl PGF a EXAMPLE XVI To a solution cooled to l5 of mg. (0.187 mmole) of the chromatographed bis-THP ether of Example XIV in 2.0 ml. of acetone was added dropwise 0.1 ml. of Jones reagent. The mixture was stirred for 30 minutes in the cold then was quenched by the addition of 0.5 ml. of 2-propanol. The solution was diluted with ethyl acetate, then was washed with water (2X) and saturated brine lX was dried (anhydrous magnesium sulfate). and was concentrated to afford 82 mg. (78 percent yield) of an oily ketone. The crude oil was purifled by column chromatography on silica gel (Baker Analyzed Reagent 60200 mesh) using 10 percent ethyl acetate in chloroform as eluent which afforded 56 mg. (53.4 percent yield) of purified oily ketone 4a- (tetrahydropyran-Z-yloxy)-3B-[3B-methyl-3a- (tetrahydropyran-Z-yloxy)-trans-1-octen-l-yl]-2a-[6- (tetrazol-S-yl)-cis-2-hexen-l-yllcyclopentanone. Thin layer chromatography of the oily product on silica gel glass plates using [0 percent methanol in methylene chloride as eluent showed a single spot having an R,= 0.55.

The structure was confirmed by the virtual identity of its ir spectrum with that of the 15-normethyl compound (see Example IV).

EXAMPLE XVII A solution of 57 mg. (0.10 mmole) of the chromatographed bis-THP ether of Example XVI in 0.88 ml. of a 65:35 mixture of acetic acid:water was stirred at 42 for 4.0 hours then was concentrated by rotary evaporation. Chromatography of the crude product weighing 48 mg. on silica gel (Mallinckrodt CC-4) using 2 percent methanol in chloroform as eluent afforded 13 mg. (33.4 percent yield) of oily 4a-hydroxy-3B-[3ahydroxy-3B-methyl-trans-l-octen-l-yl1-2a-[6- (tetrazol-5-yl)-cis-2'hexen-l-yl]cyclopentanone. This compound is the 2-descarboxy-2-(tetrazol-5-yl)-l5- methyl PGE The structure was substantiated by the practical identity of its ir spectrum to that of the l5-normethyl compound. Treatment of a methanolic solution of the oily product with 40 percent aqueous potassium hydroxide afforded the expected uv absorption at 278 mu 20,000).

The tetrazoyl analog of IS-methyl PGE may be converted by the process of Example IX to 4B-(3ozhydroxy-3 B-methyl-transl-octenl -yl )5 a-[ 6- (tetrazol-S-yl)-cis-2-hexen-l yl}cyclopent 2ene-l-one, the Z-descarboxy-2-(tetrazol-5-yl)-l5-methyl PGA The tetrazoyl analog of IS-methyl POE may be converted by the process of Example XXIII to the 2- descarboxy-2-(tetrazoyl-S-yl)lS-methyl PGF a EXAMPLE XVIII A mixture of the chromatographed bis-THP ether of Example II (I30 mg, 0.23 mmole), 5 percent palladium on carbon (32.5 mg), and methanol (13 ml.) is

stirred magnetically under one atmosphere of hydrogen at l 5 to C. for 3.0 hours. The resulting mixture is filtered through Celite 545, and the filtrate is concentrated (ca. 30-40, aspirator pressure) to afford the colorless. oily la-hydroxy-4a-(tetrahydropyran-Z- yloxy)-3/3-{ 3a-(tetrahydropyran-Z-yloxy )-trans l octen l-yl] 2a-[6-(tetrazol-5-yl)-hex-lyl]cyclopentane (herein called Compound C).

This compound C may be converted by the process of Example III to 3B-(3a-hydroxy-trans-l-octen-l-yl)- 2o:[ 6-( tetrazol-5-yl)hexl -yl lcyclopentanl a,4a-diol, the 2-descarboxy-2-(tetrazol-S-yl) IGF a Compound C above may also be converted by the processes of Examples IV and V to 4ahydroxy-3B- (3ahydroxy-trans-l-octen-l-yl)-2a-(6 (tetrazol5- y])hex-l-yl]cyclopentanone, the Z-descarboxy-Z (tetrazol-S-yl) PGE,.

The tetrazoyl analog of PGE may be converted by the process of Example IX to 4B-(3a-hydroxy-trans-locten-l-yl)5oz-[6 (tetrazol-5yl)hex-l-yl]cyclopent-2- en-I-one, the 2-descarboxy-2-(tetrazol-S-yl) PGA The tetrazoyl analog of PGE, may be converted by the process of Example XXIII to the Z-descarboxy-L (tetrazol-S-yl) PGF B EXAMPLE XIX A mixture of the known 2-[5a-hydroxy-3a- (tetrahydropyran-2-yloxy)2[3-(3a-(tetrahydropyran- 2-yloxy)-trans- 1 -octenl -y] )cyclopentanl a-yl]acetic acid, y-lactone (0.840 g, 1.92 mmoles), 5 percent palladium on carbon (0.10 g.) and absolute ethanol ml.) is stirred magnetically under I atmosphere of hydrogen at room temperature for 5 hours. The resulting mixture is filtered, and the filtrate is concentrated to afford a thick, colorless oil, Z-[Sa-hydroxy-Sa- (tetrahydropyran-2-yloxy)-2B-(3a-(tetrahydropyran- 2-yloxy)oct- I -yl)cyclopentanl oz-yl]acetic acid, y-lactone. The compound is converted by the method of Example XIII to 2-[5oz-hydroxy-3a-(tetrahydropyran-Z- yloxy)-2B-( 3o:-(tetrahydropyran-Z-yloxy)octl yl )cyclopentanl a-yllacetaldehyde, y-hemiacetal.

This compound is converted by the method of Example II to 3B-[3a-(tetrahydropyran-Z-yloxy)oct-l-yl]- 2a-[6-(tetrazol-5-yl)-cis-2-hexen-l-yl]-4a- (tetrahydropyran-2-yloxy)cyclopentanol (herein called compound D).

Compound D may be converted by the process of Example III to 3B-(3a-hydroxyoct-l-yl)-2a-[6-(tetrazol- 5-yl)-cis-2-hexen-l-yl]cyclopentan-la,4a-diol, the 2- descarboxy-2-(tetrazol-S-yl)l3,l4-dihydro PGF or Compound D may be converted by the process of Examples IV and V to 4a-hydroxy-3B-( 3a-hydroxyoct-lyl)-2a-[6-(tetrazol-5-yl)-cis-2-hexen-l-yll cyclopentanone, 2-descarboxy-2-(tetrazol-S-yl)-I 3,14- dihydro PGE The tetrazoyl analog of l3,l4-dihydro PGE may be converted by the process of Example IX to 4/3-(3ahydroxyoct-l-yl)-5a-[6-(tetrazol-5-yl)-cis-2-hexen-1- yllcyclopent-2-en- I one, the 2-descarboxy-2-(tetrazol- 5-yl)-l 3,1 4-dihydro PGA The tetrazoyl analog of 13,14-dihydro PGE may be converted by the process of example XXIII to the 2- descarboxy-2-(tetrazol-5-yl)-l 3,14-dihydro PGF p EXAMPLE XX A mixture of 2.68 g. (6.00 mmoles) of the 'y-lactone starting material of Example X and 0.636 g. of IO percent palladium on carbon in 29 ml. of absolute ethanol was stirred under 1 atmosphere of hydrogen at ambient temperature for 5 hours, then the mixture was filtered through Celite 545. Concentration of the filtrate afforded the desired 2-[3a-p-biphenylcarboxy-5ahydroxy-2B-[ 3-oxooctl -yl ]cyclopentl a-yllacetic acid, y-lactone.

This compound may be converted by the process of Example X to 2-I3a-p-biphenylcarboxy-5a-hydroxy- 2B-[ 3a-hydroxy-3B-methyloctl -yl]cyclopental ayl]acetic acid, "y-lactone, which may be converted by the process of Example XI to 2-[3a,5a-dihydroxy-2B- (3a-hydroxy-3B-methyloct-l-yl)cyclopenta-layl]acetic acid, 'y-lactone.

The latter compound may be converted by the process of Example XII to 2-[5a-hydroxy-3a- (tetrahydropyran-2-yloxy)-2B-(3B-methyl-3a- (tetrahydropyran-Z-yloxy)oct-l-yl)cyclopentan-1ozyl]acetic acid, 'y-lactone which may be converted by the process of Example XIII to 2-[5a-hydroxy-3a- (tetrahydropyran-2-yloxy-2B-( 3/3-methyl-3a- (tetrahydropyran-Z-yloxy )octl -yl)cyclopentl ayl]acetaldehyde, 'y-hemiacetal.

The latter compound may be converted by the process of Example XIV to la-hydroxy-4a- (tetrahydropyran-Z-yloxy )-3B-[ 3B-methyl-3a- (tetrahydropyran-2-yloxy)octl -yl ]-2a-[6(tetrazol-5- yl)-cis-2-hexen-l-yl]cyclopentane (herein called compound E), an important intermediate in the synthesis of l 3, l 4-dihydrol 5-lower alkyl tetrazoyl analogs of prostaglandins.

Compound E is converted by the process of Example XV to la,4a-dihydroxy-3B-[3oz-hydroxy-3/3- methyloct-l-yl]-2a-[6(tetrazol-S-yl)-cis-2-hexen-lyl]-cyclopentane, the 2-descarboxy-2-(tetrazol-5-yl)- l3,l4dihydro-l5-methyl PGF a Compound E above may be converted by the process of Example XVI to 4a-(tetrahydropyran-Z-yloxy)-3B- [3B-methyl-3a-(tetrahydropyran 2 yloxy)oct-l-yl]-2a [6-(tetrazol-5-yl)-cis2-hexen-l-yllcyclopentanone, an intermediate, which may be further converted by the process of Example XVII to 4oz-hydroxy-3B-[3orhydroxy-IlB-methyloct- I -yl]-2a-[6-(tetrazol-5-yI)-cis- 2-hexen-l yl]-cyclopentanone, the 2-descarboxy-2- (tetrazol-5-yl)-l 3,] 4dihydro-l S-methyl PGE The latter prostaglandin analog may be converted by the process of Example IX to 4B-[3a-hydroxy-3fimethyloctl -yl]-5oz-[6-(tetrazol-5-yl )-cis-2-hexenl yllcyclopent-2-en-l-one, the 2-descarboxy-2-(tetrazol- 5-yl)-l3,l4-dihydro-lS-methyl PGA The 2-descarboxy-2-(tetrazol-S-yl)-13,14-dihydrol5-methyl PGE analog may be converted by the process of Example XXIII to the 2-descarboxy-2-(tetrazol- 5-yl)-l3,l4-dihydro-lS-methyl PGF p EXAMPLE XXI The known compound 2-[5a-hydroxy-3a- (tetrahydropyran-Z-yloxy )-2B-( 3oz-(tetrahydropyran- 2-yloxy)-cis-5-transl -octadienl -yl )cyclopentl ayllacetaldehyde, 'y-hemiacetal (see E. 1. Corey, et al,

J. Amer. Chem. Soc., 93, I490 (I971) may be converted by the process of Example XI to la-hydroxy-SB- [3a-( tetrahydropyran-2-yloxy)-trans-l -cis-5-octadienl-yIl-Za-l6-(tetrazol-5-yl)-cis-2-hexen-l-yl]-4a- (tetrahydropyran-2-yloxy)cyclopentane, an important intermediate in the synthesis of tetrazoyl analogs of the P6 series, herein called compound F.

Compound F may be converted by the process of Example III to 3B-(30z-hydroxy-transl -cis-5-octadienl yl)-2a-[6-(tetrazoI-5-yl)-cis-2-hexen-l-yI)]-cyclopentan-la,4a-diol, the 2-descarboxy-2-(tetrazol-S-yl) PGF3 a Compound F above may be converted by the process of Example IV to 4a-(tetrahydropyran-2-yloxy)-3B- [3a-( tetrahydropyran-2-yloxy )-transl -cis-5-octadien- I-yl]cyclopentanone, an intermediate which may be converted by the process of Example V to 4a-hydroxy 3B-( 3a-hydroxy-transl -cis-5-octadien l -yl)-2a-[ 6- (tetrazol-S-yl )-cis-2-hexenl -yl lcyclopentanone, 2-descarboxy-2-(tetrazol-S-yl) PGE The latter prostaglandin analog may be converted by the process of Example IX to 4B-(3a-hydroxy-trans-lcis-S-octadien-l-yl)-5a-[6-(tetrazol-S-yl-cis-2-hexenl-yl]cyc1opent-2-en-l-one, the 2-descarboxy-2- (tetrazol-S-yl) PGA EXAMPLE XXII To a solution of 58 mg (0.l54 mmole) of the 2- descarboxy-2(tetrazol-S-yl)PGE prepared in Example V in 5 ml. of ethyl acetate was added dropwise a solu tion of diazomethane in ether (ca. 0.3 ml prepared from N-methyl-N'-nitro-N-nitrosoguanidine according to the procedure found in Fieser and Fieser, Reagents for Organic Synthesis", Volume 1, page I92). The yellow solution was stirred for 5 minutes then was concentrated by rotary evaporation to afford a clear tan oil. Purification of the crude product by column chromatography (Baker Analyzed silica gel 60-200 mesh) the using mixtures of methanol in chloroform afforded 29 mg. of 2-descarboxy-2-(Z-N-methyltetrazol-S-yl)PGE and 7 mg. of 2-descarboxy-2-( l-N-methyltetrazol-S- yl)PGE The ir spectra (CHCl of both products were superimposable exhibiting strong absorbances at I740 cm'l (C O) and 965 cml (trans olefin).

The uv spectra (EtOH) of both products after treatment with KOH showed a A at 278 nm with an 23,500.

EXAMPLE XXIII To a solution, cooled in ice, of 35 mg of the 2- descarboxy-2-(tetrazol-S-yUPGE prepared in Exam ple V in 7 ml. of absolute methanol was added an icechilled solution of 105 mg. of sodium borohydride in 12 ml. of absolute methanol. The solution was stirred under nitrogen for 20 minutes at 0-5 then for ID hour at room temperature. The reaction mixture was then cooled in ice, 2 ml. of water was added, and the resultant solution was concentrated. The concentrated mixture was overlaid with ethyl acetate, was acidified with 10 percent hydrochloric acid, and the acidified aqueous layer was extracted with ethyl acetate (4 X 5 ml.). The combined extracts were washed with water and saturated brine, were dried (anhydrous magnesium sulfate), and were concentrated. The crude residue was purified by column chromatography (Mallinckrodt CC-7) using mixtures of methanol in methylene chloride as eluents to afford first 2-descarboxy-2-(tetrazol- 5-yl)PGF then 2-descarboxy-2 -(tetrazol-5- yl)PGF p as viscous, colorless oils. The ir spectra (CI-ICI of the two products were superimposable.

EXAMPLE XXIV A heterogeneous mixture of 2.24 g. (5.0 mmoles) of the known (E. J. Corey, et al., .IACS, 93. I491 (I97 I) 2-[5a-hydroxy-3a-p-phenylbenzoyloxy-2/3-(3B- hydroxy-trans-octen-I -yl)cyclopent- I a-yl]acetic acid, y-lactone and 0.680 g (5.0 mmoles) of anhydrous potassium carbonate in 22 ml. of absolute methanol was stirred at room temperature under nitrogen for 2.0 hours. The reaction mixture was then cooled in ice and was quenched by the addition of 10 ml. of LON aqueous hydrochloric acid. The quenched mixture was di- Iuted with water (22 ml.) and filtered to remove the precipitated methyl p-phenylbenzoate The filtrate was extracted with ethyl acetate (3 X 5 ml.); the combined organic extracts were washed with saturated sodium bicarbonate and saturated brine, were dried (anhydrous magnesium sulfate), and were concentrated to afford the desired 2-[3a,5a-dihydroxy-2B-(3B- hydroxy-transl -octenl -yl )cyclopentl a-yl]acetic acid, y -lactone as a viscous oil weighing [.17 g. (87.4 percent yield). The ir and nmr spectra of the product were superimposable on those of the known I511 epimer.

The starting material above may be reduced by the procedure of Example XXXII to the 2-[2B-(3B- hydroxy-transl -octenl -yl )-3a,5a-dihyd roxycyclo- [301-p phenylbenzoyloxy-2B-(3B-(3B-hydroxyoct-1- yll-Sa-hydroxycyclopentla-yl]acctic acid, y-lactone.

This compound may be reduced as described in Example XXXll to Z-l3a,5a-dihydroxy-2B-(3B- hydroxyoct-l-yl)cyclopent1a-yl]acetaldehyde, y-hemiacetal.

This compound may be converted to lS-epi-Z descarboxy-2(tetrazol-5-yl)-13,14-dihydro PGF a following the method of Example XXXlll.

EXAMPLE XXV To a solution of 1.17 g. (4.37 mmoles) of the 2- [3a.5a-dihydroxy-2B(3B-hydroxyl-trans-l-octen-lyl)cyclopent-la-yllacetic acid, y-lactone prepared above in Example XXIV and 1.17 ml. 2.3- dihydropyran in 12 ml. of methylene chloride was added 12 mg. of p-toluensesulfonic acid monohydrate. The reaction was stirred under nitrogen at room temperature for 15 minutes then was diluted with ether (100 ml.). The diluted solution was washed with saturated sodium bicarbonate and saturated brine, was dried (anhydrous magnesium sulfate). and was concentrated to afford the desired 2-[5a-hydr0xy-3a (tetrahydropyran-2-yloxy)-2B-(BB-(tetrahydropyranl-yloxyHrans-octen-1-yl)cyclopent-la-yllacetic acid, 'y-lactone as a viscous oil weighing 2.10 g. 100 percent yield). The ir and nmr spectra were superimposable on those of the known 15a-epimer.

EXAMPLE XXV] A heterogeneous mixture of 2.02 g. of the 2-[5ahydroxy-3w(tetrahydropyran-Z-yloxy)2B-(3B- (tetrahydropyran l-yloxy)-trans-1-octenly1)cyc1opent-la-yllacetic acid, y-lactone prepared above and 202 mg. of 5 percent palladium on carbon in ml. of absolute methanol is stirred under 1 atmosphere of hydrogen for 4.5 hours at room temperature. The mixture is then filtered (Celite); concentration of the filtrate provides the desired 2-[5a-hydroxy-3a- (tetrahydropy ran-Z-yloxy )-2[3-( 3;8-( tetrahyd ropyran- 2-yloxy)oct-1-yl)-cyclopent-la-y1]acetic acid, 'y-lac tone.

This compound may be reduced as follows in Example XXVII to provide the hemiacetal useful for the preparation of the 15-epi-13,l4-dihydro PGE PGF a PGF 5 and PGA tetrazole analogs.

EXAMPLE XXVII To a solution, cooled to 78 under nitrogen, of 1.90 M

g. (4.37 mmoles) the 2 [5a-hydroxy-3a- (tetrahydropyran-Z-yloxy)-2/3-(3B-(tetrahydropyranl-yloxyytrans-octend-yl)cyclopent-lwyl]acetic acid, y-lactone prepared above in Example XXVI in ml. ofdry toluene was added dropwise 5.92 ml. ofa 20 percent solution of diisobutylaluminum hydride in hexane (Alfa lnorganics). The reaction was stirred for 45 minutes at 78 then was quenched by the dropwise addi tion of methanol until gas evolution ceased. The quenched reaction was let warm to room temperature, was diluted with ether, was washed with a 50 percent sodium potassium tartrate solution and with saturated brine, was dried (anhydrous magnesium sulfate), and was concentrated to provide a viscous, yellow oil which was purified by column chromatography (Baker Silica Gel 60200 mesh) using mixtures of benzene2ethyl acetate as eluents. After removal of less polar impurities the desired 2-[5a-hydroxy 3a-(tetrahydropyran- 2- yloxy )-2B-( 3B-(tetrahydropyran-2-yloxy trans-octenl-yl)cyclopentla-yllacetaldchydc, 'y-hcmiacetal was collected as a colorless oil weighing 159 g. (83.5 per cent yield). The ir and nmr spectra were superimposable on those of the known l5a-epimer.

This compound may be converted into the l5-epi 2- descarhoxy-2-(tetrazol-S-yl) PGE PGFg a PGF PGA PGE,, PGF, ,PGF PGA 13,14-dihydro PGE,,PGF ,PGF, ,3 and PGA,.

EXAMPLE XXVlll Dimethyl 2-Oxo-undecylphosphonate:

A solution of 49.6 g. (0.40 mole) dimethyl methyl phosphonate (Aldrich) in 500 ml. dry tetrahydrofuran is cooled to 78 in a dry nitrogen atmosphere. To the stirred phosphonate solution is added 188 ml. of 2.34 M n-butyllithium in hexane solution (Alfa lnorganics, lnc.) dropwise over a period of 40 minutes at such a rate that the reaction temperature never rose above After an additional 5 minutes stirring at 78, 36.3 g. (0.20 mole) methyl decanoate is added dropwise at a rate that kept the reaction temperature less than 7U (20 minutes). After 1.0 hour at 7S the reaction mixture is allowed to warm to ambient temperature, neutralized with 25 m1. acetic acid and rotary evaporated to a white gel. The gelatinous material is taken up in 75 ml. water, the aqueous phase extracted with 100 ml. portions of chloroform (3X), the combined organic extracts are backwashed 50 cc H O), dried (MgSo and concentrated (water aspirator) to a crude residue and distilled, to give dimethyl 2-oxoundecylphosphonate.

This compound may be converted by methods both known (see: E. 1. Corey, et al., J. Am. Chem. Soc., 92, 397 (1970) and described herein to the Z-descarboxy- 2 (tetrazol-5-yl)- i -tetrahomo PGE a PGF PGF; PGA PGE,, PGF, 5 ,PGRB ,PGA 13,14-dihydro PGE 13,14-dihydro PGF 13,14- dihydro PGF a 13,14-dihydro PGA 13,14-dihydro PGE 13,14-dihydro PGF B 13,14-dihydro PGF 13,14-dihydro PGA the corresponding l4-epimers, and 15-1ower alkyl analogs.

EXAMPLE XXIX Dimethyl Z-Oxo-3,3-dimethylheptylphosphonate:

A solution of 18.4 g. (0.116 moles) dimethyl methylphosphonate (Aldrich) in 200 ml. dry tetrahydrofuran is cooled to 78 in a dry nitrogen atmosphere. To the stirred phosphonate solution is added 673 ml. of 1.90 M n-butyllithium in hexane solution (Alfa lnorganics, lnc.) dropwise over a period of 40 minutes at such a rate that the reaction temperature never rose above 65. After an additional 5 minutes stirring at 78, 10.2 g. (58.1 mmoles) methyl 2,2-dimethylhexanoate is added dropwise at a rate that kept the reaction temperature less than (20 minutes). After 1.0 hour at 78 the reaction mixture is allowed to warm to ambient temperature, neutralized with 10 ml. acetic acid and rotary evaporated to a white gel. The gelatinous material is taken up in ml. water, the aqueous phase extracted with 100 ml. portions of chioroform (3x), the combined organic extracts are backwashed (50 cc H O), dried (MgSO and concentrated (water aspirator) to a crude residue and distilled (b.p. 8085 at 0.05 mm) to give dimethyl 2-oxo-3,B-dimethylheptyl phosphonate.

This compound may be converted by methods both known (see: E. J. Corey, et al., J. Am. Chem. Soc., 92, 397 (1970) and described herein to the 2-descarboxy- 2-(tetrazol-5-yl)-16,16-dimethyl PGE a PGF p PGF B PGA PGE,, PGF, ,PGF a ,PGA,, 13,14-dihydro PGE 13,14-dihydro PGF p 13,14- dihydro PGF a 13,14-dihydro PGA l3,l4-dihydro PGE,, 13,14-dihydro PGF p 13,14-dihydro PGF l3,l4-dihydro PGA,, the corresponding lS-epimers, and l5-lower alkyl analogs.

EXAMPLE XXX To a solution of 76 mg. (0.2 mmole) of the 2- descarboxy-2-(tetrazol-S-yl)PGF prepared in Example lll in 1.0 ml. of pyridine is added 120 mg. (1.0 mmole) of pivaloyl chloride. The solution is stirred for 5 hours at 45 under nitrogen then is cooled to room temperature. To the solution is then added 36 mg. (2.0 mmoles) of water. The solution is then stirred at room temperature for 2.0 hours, then is diluted with ethyl acetate. The diluted solution is washed with 0.1 N hydrochloric acid (3x), with water 1x), and with saturated brine (1x), is dried (anhydrous magnesium sulfate), and is concentrated. Purification of the crude residue by silica gel chromatography provides the desired 9a,] 1a, l5a-tris-pivaloyloxy-2-descarboxy-2-(tetrazol- EXAMPLE XXXl To a solution of 37 mg. (0.l mmole) of 2- descarboxy-2-(tetrazol-S-yl)PGE prepared in Example V in 0.5 ml. of dry tetrahydrofuran is added 29 mg. (0.33 mmole) of formic acetic anhydride and 35 mg. (0.33 mmoles) of 2,6-lutidine. The solution is stirred for 4 hours under nitrogen at room temperature then 36 mg. (2.0 mmoles) of water is added. The mixture is stirred at room temperature for an additional 1.0 hour then is diluted with ethyl acetate. The diluted solution is washed with 0.1 N hydrochloric acid 1x), with water (1x), and with saturated brine 1x), is dried (anhydrous magnesium sulfate), and is concentrated. Purification of the crude residue by silica gel chromatography affords the l 1a,]Sa-bis-formyl-Z-descarboxy Z-(tetrazol- 5-yl)PGE EXAMPLE XXXll 2-[2B-( 3a-hydroxy-trans- 1 -octenl -yl)-3a,5adihydroxycyclopentl a-yl]acetaldehyde, y-hemiacetal:

To a solution cooled to 78 of 866 mg. (1.93 mmoles) of the known 2-[3a-p-phenylbenzoyloxy-Sahydroxy-2B-(3a-hydroxy-transl-octen-lyl)cyclopent-la-yl]acetic acid, 'y-lactone in 12 ml. of toluene was added 4.82 ml. (3.88 mmoles) of a 0.805 M solution of diisobutylaluminum hydride in hexane. The reaction was stirred in the cold under nitrogen for 30 minutes then was quenched by the addition of methanol (0.5 ml.). The reaction was let warm to room temperature then was concentrated to a white semisolid. The semisolid was slurried with methanol (3x), was filtered through Celite 545, and was concentrated. Purification of the crude product by silica gel chromatography using mixtures of chloroformzethyl acetate as eluents afforded the desired 2-[2B-(3a-hydroxy-trans-locten-l-yl)-3a,5a-dihydroxycyclopent-layl]acetaldehyde, y-hemiacetal as a colorless oil weighing 304 mg. (59.5 percent yield).

The ir spectrum (CHCL of the product exhibited strong adsorptions at 970 cml (trans olefin) and 3380 cml (OH). The nmr spectrum (CDCL showed multiplets at 5.64-5.20 8 (2H) for the trans olefin, at 4.66-4.22 8 1H) for the O-Cfl 0, at 4.18-3.19 8 (3H) for the OCfl, and at 2.62-0.40 8 (20H) for the remaining protons.

EXAMPLE XXXlll 30:,5a-dihydroxy-l 2B-( 3a-hydroxy-transl -octenl yl)-la[6-(tetrazol-5-yl]-cis-2-hexen yl]cyclopentane:

To a solution 2.91 g. (6.25 mmoles) of [4-(tetrazol- 5-yl)-n-butyl]triphenylphosphonium bromide in 3 ml. of dimethyl sulfoxide is added 6.00 ml. (12.0 mmoles) of a 2.0 M solution of sodium methylsulfinylmethide in dimethyl sulfoxide. The resultant red ylide solution is stirred for 10 minutes then a solution of 338 mg. (1.25 mmoles) ofthe trio] of Example XXXll in 2.0 ml. of dimethyl sulfoxide is added dropwise. The mixture is stirred at room temperature under nitrogen for 4 hours then is poured onto a mixture of ethyl acetate icewater. The aqueous layer is acidified with 10 percent aqueous hydrochloric acid and is extracted with ethyl acetate; the combined organic extracts are washed with water and saturated brine, are dried (anhydrous magnesium sulfate), and concentrated. Purification of the crude product by silica gel chromatography provides the desired 3a,5a-dihydroxy-2B-(3a-hydroxy-trans-locten1-yl)-la-[7(tetrazol-S-yl)-cis-2-hepten-l-yl] cyclopentane. This compound is 2-descarboxy-2- (tetrazol-S-yUPGF a -yl)PGF EXAMPLE XXXlV 2-[3a-p-phenylbenzoyloxy-2B-( 3a-hydroxyoctl -yl Sa-hydroxycyclopentl a-yllacetic acid, ylactone A heterogeneous mixture of 954 mg. (2.14 mmoles) of the known 2-[3a-p-phenylbenzoyloxy-Sa-hydroxy- 2B-( 3a-hydroxy-transl -octen l -yl )cyclopentlayl]acetic acid, 'y-hemiacetal and mg. of 10 percent palladium on carbon in 10 ml. of absolute methanol is stirred under one atmosphere of hydrogen at room temperature for 4.5 hours. The mixture is then filtered through a pad of Celite and concentrated to afford the desired 2-[ 3E1p-phenylben2oyloxy-2a-( 3ahydroxyoctl -yl)-5a-hydroxy-cyclopentl a-yl ]acetic acid, y-lactone.

This compound may be reduced as described in Example XXXII to 2-[ 3a,5a-dihydroxy-2B( 3ahydroxyoct-l-yl)cyclopent-la-yllacetaldehyde, y-hemiacetal.

This compound may be converted to 2-descarboxy2 (tetrazol-5-yl)-l3,14-dihydro PGF a following the method of Example XXXlll.

EXAMPLE XXXV 5a-hydroxy-2B-benzyloxymethyl-3a-(tetrahydropyran- 2-yloxy)-la-[6-(tetrazol-5-yl)-cis-l-hexen -ly1]cyclopentane To a solution of 7.06 g. (15.0 mmoles) of [4- (tetrazol-S-yl)butyl]triphenylphosphonium bromide in 14 ml. of dimethyl sulfoxide is added dropwise 15.0 ml. of a 2.0 M solution of sodium methylsulfinylmethide in dimethyl sulfoxide. To the resultant red ylide solution is added dropwise a solution of 1.76 g. (5.0 mmoles) of the known 2-[2B-benzyl0xymethyl-3a- (tetrahydropyran-Z-yloxy)-a-hydroxycyclopent-1ayl]acetaldehyde, 'y-hemiacetal in 17 ml. of dimethyl sulfoxide. After being stirred for 12 hours under nitrogen at room temperature the reaction is poured onto ice-water. The aqueous solution is overlaid with ethyl acetate, is acidified to pH- 3 with percent aqueous hydrochloric acid, and is extracted with ethyl acetate. The combined ethyl acetate extracts are washed with water, dried (anhydrous magnesium sulfate), and concentrated. Purification of the crude product by silica gel chromatography provides the desired Sa-hydroxy- ZB-benzyloxymethyl-3a-(tetrahydropyranQ-yloxy)- 1a-[6-(tetrazol-5-yl)-cis-1-hexenl-yllcyclopentane.

EXAMPLE XXXVI 5a-acetoxy-2[3-benzyloxymethyl-3o:-(tetrahydropyran- 2-yloxy)-1a-[6-(tetrazol5-yl)-cis-1hexen -1- yl]cyclopentane A mixture of 1.66 g. (3.45 mmoles) of the chromatographed alcohol of Example XXXV, 5.0 ml. of pyridine and 0.736 ml. (7.78 mmoles) of acetic anhydride is stirred under nitrogen at 50 for 18 hours. The mixture is then cooled to room temperature and diluted with ethyl acetate. The organic solution is washed with 10 percent hydrochloric acid then water, is dried (anhydrous magnesium sulfate), and is concentrated. Purification of the crude product by silica gel chromatography provides the desired 5a-acetoxy-2B- benzyloxymethyl-3a-(tetrahydropyran-2-yloxy)- 1 01-16- (tetrazol-5-yl)-cis- 1 -hexen -1-yl1cyclopentane.

EXAMPLE XXXVll 5a-acetoxy-ZB-hydroxymethyl-3a(tetrahydropyran-2- yloxy)-1a-[6-(tetrazol-5-yl)-hex -1 yl}cyclopentane A heterogeneous mixture of 1.62 g. (3.14 mmoles) of the chromatographed benzyl ether of Example XXXVI, 324 mg. of 5 percent palladium on carbon, and 16.2 ml. ofa 20:1 mixture of absolute ethanolzglacial acetic acid is stirred at room temperature under one atmosphere of hydrogen for 8 hours. The mixture is then filtered through Celite 545 and the filtrate is concentrated and is azeotroped under reduced pressure with toluene. Purification of the crude product by silica gel chromatography affords the desired 5aacetoxy-2B-hydroxymethy1-3a-(tetrahydropyran2- yloxy)-1a-[6-(tetrazol-5-yU-hex -l-yl]cyclopentane.

EXAMPLE XXXVIll Sa-acetoxy-ZB-formyl-301-(tetrahyclropyran-2-yloxy)- 1a-[6-( tetrazol-5'yl)-hex -l-yl]cyclopentane To a mechanically stirred solution of 3.37 ml. (41.7 mmoles) of pyridine in 50 ml. of methylene chloride, cooled to 10 to under nitrogen, is added portionwise over a period of 30 minutes 1.89 g. (18.9 mmoles) of chromium trioxide. The dark burgundy solution is let warm to room temperature then is cooled to 0. To the cold solution is added a solution of 1.01 g. (2.37 mmoles) of the alcohol of Example XXXVll is 7.0 ml. of methylene chloride with the concomitant formation of a dense black precipitate. The suspension is stirred in the cold for 15 minutes then 7.21 g. (52.2 mmoles) of finely ground sodium bisulfite monohydrate is added. After being stirred for 10 minutes 6.52 g. (52.2 mmoles) of anhydrous magnesium sulfate is added.

After being stirred for 5 minutes the dark suspension is filtered through a pad of Celite, is washed with methylene chloride, then is concentrated to afford the desired 5a-acetoxy-2B-formyl-3a-(tetrahydropyran-Lyloxy)- 1a-[6-(tetrazol-5-yl)-hex -1-yl]cyclopentane which is used without purification.

EXAMPLE XXXlX 5a-acetoxy-2B-(3-oxo-trans-1-octen-1-y1)-3a- (tetrahydropyran-2-yloxy)-1a-[6-(tetrazol-5-yl)-hex -1-yl]cyclopentane To a suspension of 220 mg. (5.22 mmoles) ofa 57.0 percent dispersion of sodium hydride in mineral oil in 40 ml. of 1,2-dimethoxyethane is added 1.16 g. (5.22 mmoles) of dimethyl-2-oxoheptylphosphonate. The mixture is stirred at room temperature for 1 hour under nitrogen with the concomitant formation of a dense white precipitate. To this suspension is added a solution of 1.13 g. (2.37 mmoles) of the aldehyde of Example XXXVll] in 4 ml. of 1,2-dimethoxyethane. The solution is stirred at room temperature for 2.0 hours under nitrogen then is quenched by the addition of glacial acetic acid to pH- 5 and is concentrated. Purification of the crude product by silica gel chromatography gives the desired 5a-acetoxy-2B-(3-oxo-trans-1-octen-l-yl)- 3a-( tetrahydropyran-Z-yloxy)- loz-[6-(tetrazol-5-yl hex -1-y1]cyclopentane.

' EXAMPLE XL 5a-acetoxy 2B-(3a-hydroxy-trans-1-octen-1-yl)-3a- (tetrahydropyran-Z-yloxy)-1a-[6-(tetrazol-5-yl)-hex -1-yl]cyclopentane To a solution, cooled to 78, of 852 mg. (2.0 mmoles) of the enone of Example XXXlX in 20 ml. of tetrahydrofuran is added 16 ml. (4.0 mmoles) of a 0.25 M solution of lithium tri-sec butylborohydride in tetrahydrofuran. The solution is stirred at 78 under nitrogen for 1.0 hour then is quenched by the addition of 10 ml. of 40 percent aqueous acetic acid. The quenched reaction mixture is let warm to room temperature and is extracted with ethyl acetate; the combined organic extracts are washed with water and saturated brine, are dried (anhydrous magnesium sulfate), are concentrated, and azeotroped with toluene. Purification of the crude product by silica gel chromatography provides the 5a-acetoxy-2B-(3oi-hydroxy-trans-1-octen-1-y1)- 3a-(tetrahydropyran-2-yloxy)-la-[6-(tetrazol-5-y1)- hex -1-yl}cyclopentane and the 5a-acetoxy-2B-( 3B- hydroxy-trans-l-octen1-yl)-3a-(tetrahydropyran-2- yloxy)-1a-[6-(tetrazo1-5 -yl)hex -1-yl]cyclopentane.

The 5a-acetoxy-2B-(3B-hydroxy-trans-1-octen-1-y1)- 3a-(tetrahydropyran-Z-yloxy)-1a-[6-(tetrazol-5- yl)hex l -yl]cyclopentane may be converted by the procedures in Examples XLl to XLlX to 15-epi-2- descarboxy-2-(tetrazol-5-yl)PGE, and PGF EXAMPLE XLI 5a-hydroxy-2B-(3oz-hydroxy-trans-1-octen-1-yl)-3a- (tetrahydropyranQ-yloxy)-1a-[6-(tetrazol-5-yU-hex -1-yl]cyclopentane A mixture of 522 mg. (1.00 mmole) of the THP ether of Example XL, 3.0 ml. (3.0 mmoles) of 1.0 N aqueous sodium hydroxide, 3.0 ml. of tetrahydrofuran, and 3.0 ml. of absolute methanol is stirred under nitrogen at room temperature for 1.5 hours. The solution is then acidified by the addition of 3.0 ml. of 1.0 N hydrochloric acid and is extracted with ethyl acetate. The combined extracts are dried (anhydrous magnesium sulfate) and concentrated. Purification of the crude product by silica gel chromatography affords the desired a-hydroxy-2B-( 3a-hydroxy-transl -octenl -yl)-3a- (tetrahydropyran-2-yloxy 1 a-[6-(tetrazol-5-yl )-hex l -yl]cyclopentane.

EXAMPLE XLll 5a-hydroxy-2B-( 3a-hydroxy-transl -octen-l yl )-3ahydroxy-l a-[6-(tetrazo1-5-yl)-hex -l-yl]cyclopentane A solution of 500 mg. of the THP ether of Example XLl in 5 ml. ofa 65:35 mixture of glacial acetic acid:- water is stirred at room temperature under nitrogen for 18 hours then is concentrated and azeotroped under reduced pressure with toluene. Purification of the crude product by silica gel chromatography gives the desired 5oz-hydr0xy-2B-(3a-hydroxy-transl -octenl yl)-3a-hydroxyl a-[6-(tetrazol-5-yl )-hex l yllcyclopentane.

EXAMPLE XLlll 5a-acetoxy-2B-( 3a-hydroxy-transl -octen- 1 -yl )-3ahydroxyl a-[ 6-( tetrazo1-5-yl)-hex l -yl]cyclopentane A solution of 1.13 g. (2.16 mmoles) of the THP ether of Example XXXIX in 11 ml. of a 65:35 mixture of acetic acidzwater is stirred at room temperature under nitrogen for 18 hours then is concentrated and azeotroped under reduced pressure with toluene. Purification of the crude product by silica gel chromatography provides the desired 5oz-acetoxy-2B-( 3a-hydroxy-transl-octen-1-yl)-3a-hydroxy-1a[6-(tetrazol-5-yl)-hex l yllcyclopentane.

EXAMPLE XLIV 5a-hydroxy-2,B-(3a-hydroxy-trans-l-octen-1-yl)-3ahydroxyl a-[ 6-(tetrazol-5-yl )hex I -y1 ]cyclopentane:

A solution of 424 mg. (1.00 mmole) of the diol of Example XLlll, 3.0 ml. (3.0 mmoles) of 1.0 N aqueous sodium hydroxide, 3.0 ml. of tetrahydrofuran, and 3.0 ml. of absolute methanol is stirred under nitrogen at room temperature for 2.5 hours. The solution is then acidified by the addition of 3.0 ml. of 1.0 N hydrochloric acid and is extracted with ethyl acetate. The combined organic extracts are dried (anhydrous magnesium sulfate) and concentrated. Purification of the crude product by silica gel chromatography provides the desired 5a-hydroxy-2B-(3a-hydroxy-trans-1-octenl-y1)-3a-hydroxyl a-[6-(tetrazol-5-yl)-hex -1- y1]cyc1opentane.

EXAMPLE XLV 5a-acetoxy-2B-(3a-(tetrahydropyran-Z-yloxy )-transl octen-l-y1)-3a-(tetrahydropyran-2-yloxy)l a-[6-(tetrazol-S-yl )-hex 1 -yl]-cyclopentane.

A solution of 250 mg. of the alcohol of Example XL, 0.250 ml. of dihydropyran, 2.5 ml. of methylene chloride, and 2.5 mg. of p-toluenesulfonic acid monohydrate is stirred at room temperature under nitrogen for minutes. The reaction mixture is then diluted with ether, is washed with water. is dried (anhydrous magnesium sulfate), and is concentrated to provide the desired 5cx-acetoxy-2B-(3a-(tetrahydropyran-Z-yloxy)- trans-1-octen-1-yl)-3a-(tetrahydropyran-Z-yloxy)-1o:- [6-(tetrazol-5-yl )-hex l -y1]cyclopentane.

EXAMPLE XLVI 5a-hydroxy-2B-( 3a-( tetrahydropyran-Z-yloxy )-transl -octen-1 -yl)-3a-(tetrahydropyran-2-yloxy)- l a-( tetrazol-5-yl)-hex -1-yl]cyclopentane A homogeneous solution of 0.265 g. (0.436 mmole) of the crude bis-THP ether of Example XLV, 1.30 ml. (1.30 mmoles) of a 1.0 N aqueous sodium hydroxide solution, 1.3 ml. of methanol, and 1.3 ml. of tetrahydrofuran is stirred at room temperature overnight. The reaction mixture is then quenched by the addition of 1.30 ml. (1.30 mmoles) ofa 1.0 N aqueous hydrochloric acid solution and is diluted with ethyl acetate. The organic layer is dried (anhydrous magnesium sulfate) and concentrated. Purification of the crude product by silica gel chromatography affords the desired 5ahydroxy-2B-( 3a-(tetrahydropyran-2-yloxy )-trans-l octen-l-yl)-3a-(tetrahydropyran-Z-yloxy)-1a-l6-(tetrazol-S-yl )-hex l -yl]cyclopentane.

EXAMPLE XLVll 5a-hydroxy-2B-( 3a-hydroxy-transl -octenl -yl)-3ahydroxyl a-[ 6-(tetrazol-5-yl)-hex l -yl]cyclopentane.

A solution of mg. of the alcohol of Example XLVl in 1.0 ml. ofa 65:35 mixture of glacial acetic acidzwater is stirred under nitrogen at room temperature for 20 hours. then is concentrated and azeotroped with toluene. Purification of the crude product by silica gel chromatography gives the desired 5a-hydr0xy-2B-(3ahydroxy-transl -octenl -yl )-3a-hydroxyl a-[ 6-(tetrazol-5-yl)-hex -l-yl]cyclopentane.

EXAMPLE XLVlll 4a-(tetrahydropyran-Z-yloxy)-2a-[6-(tetrazol-5-yl)- hex -l-yl]3B-(3a-(tetrahydropyran-Z-yloxy)-trans-locten-lyl)cyclopentanone To a solution, cooled to -23 under nitrogen. of 0.202 g. (0.371 mmole) of the alcohol of Example XLVI in 4.0 ml. of acetone is added dropwise 0.163 ml. (0.408 mmole) of Jones reagent. The reaction is stirred in the cold for 15 minutes then is quenched by the addition of 0.163 ml. of isopropyl alcohol. The quenched reaction is stirred in the cold for 5 minutes then is diluted with ethyl acetate. The organic solution is washed with water, is dried (anhydrous magnesium sulfate). and is concentrated to afford the desired 4a- (tetrahydropyran-2-yloxy)-2a-[6-(tetrazol-5-yl)-hex -l-yl]-3/3-(3a-(tetrahydropyran-Z-yloxy)-trans-1- octen-1-yl)cyclopentanone which is used without purification.

EXAMPLE XLlX 4a-hydroxy-2a-[6-(tetrazol-5-yl)-hex -1-yl]-3B-(3orhydroxy-trans- 1 -octenl -yl)cyclopentanone A homogeneous solution of0. g. of the crude bis- THP ether of Example XLVlll in 2.0 ml. of a 65:35 mixture of glacial acetic acidzwater is stirred under nitrogen at room temperature for 12 hours, then is concentrated and azeotroped with toluene. Purification of the crude product by silica gel chromatography affords the desired 4oz-hydroxy-2a-[6-(tetrazol-5-yl)-hex -1- yl}-3B-( 3a-hydroxy-transl-octen- 1 yl)cyclopentanone.

EXAMPLE L To a suspension 275 mg. (6.53 mmoles) of a 57.0 percent dispersion of sodium hydride in mineral oil in 

1. 2-DESCARBOXY-2-(TETRAZOL-5-YL)-WPENTANORPROSTAGLANDINS, AND THEIR C15 EPIMERS, AND THE CORRESPONDING 1- AND 3-LOWER ALKYLTETRAZOLY-WPENTANORPROSTAGLANDINS, AND THEIR C15 EPIMERS, HAVING AT THE 15-POSITION ONE HYDROGEN OR ALKYL SUBSTITUENT HAVING FROM 1 TO 3 CARBON ATOMS AND ONE ALKYL SUBSTITUENT HAVING FROM 5 TO 11 CARBON ATOMS, AND THE C9, C11 AND C15 ESTERS THEREOF WHEREIN SAID ESTERIFYING GROUP IS FORMYL, ALKANOYL HAVING FROM 2 TO 5 CARBON ATOMS, OR BENZOYL.
 2. 2-descarboxy-2-(tetrazol-5-yl)- omega -pentanorprostaglandins of the A, E, or F series, and their C15 epimers, and the corresponding 1- and 3-lower alkyl-tetrazolyl- omega -pentanorprostaglandins, and their C15 epimers, having at its 15-position one hydrogen or alkyl substituent having from 1 to 3 carbon atoms and one alkyl substituent having from 5 to 11 carbon atoms, and the C9, C11, and C15 esters thereof wherein said esterifying group is formYl, alkanoyl having from 2 to 5 carbon atoms, or benzoyl.
 3. A compound of the structure:
 4. A compound of the structure:
 5. A compound of the structure:
 6. A compound of the structure:
 7. A compound of the structure:
 8. A compound according to claim 6 wherein W is a single bond, Z is a trans double bond, and R1 is n-pentyl, and R is hydrogen.
 9. A compound according to claim 6 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 10. A compound according to claim 6 wherein W and Z are each single bonds, R1 is n-pentyl, and R is hydrogen.
 11. A compound according to claim 6 wherein W is a cis double bond, Z is a single bond, R1 is n-pentyl, and R is hydrogen.
 12. A compound according to claim 4 wherein W is a single bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 13. A compound according to claim 4 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 14. A compound according to claim 5 wherein W is a single bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 15. A compound according to claim 5 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 16. A compound according to claim 7 wherein W is a single bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 17. A compound according to claim 7 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is hydrogen.
 18. A compound according to claim 6 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is methyl.
 19. A compound according to claim 6 wherein W is a single bond, Z is a trans double bond, R1 is n-pentyl, and R is methyl.
 20. A compound according to claim 6 wherein W is a cis double bond, Z is a single bond, R1 is n-pentyl, and R is methyl.
 21. A compound according to claim 6 wherein W and Z are each single bonds, R1 is n-pentyl, and R is methyl.
 22. A compound according to claim 4 wherein W is a cis double bond, Z is a trans double bond, R1 is n-pentyl, and R is methyl.
 23. A compound according to claim 4 wherein W is a single bond, Z is a trans double bond, R1 is n-pentyl, and R is methyl.
 24. A compound according to claim 6 wherein W is a cis double bond, Z is a trans double bond, R1 is 1,1-dimethylpent-1-yl and R is hydrogen.
 25. A compound according to claim 6 wherein W is a single bond, Z is a trans double bond, R1 is 1,1-dimethylpent-1-yl and R is hydrogen.
 26. A compound according to claim 6 wherein W is a cis double bond, Z is a single bond, R1 is 1,1-dimethylpent-1-yl and R is hydrogen.
 27. A compound according to claim 6 wherein W and Z are each single bonds, R1 is 1,1-dimethylpent-1-yl and R is hydrogen.
 28. A compound according to claim 4 wherein W is a cis double bond, Z is a trans double bond, R1 is 1,1-dimethylpent-1-yl and R is hydrogen.
 29. A compound according to claim 4 wherein W is a single bond, Z is a trans double bond, R1 is 1,1-dimethylpent-1-yl and R is hydrogen. 